Introduction

Functional gallbladder disorder (FGBD) is a disorder of gut-brain interaction classified under the Rome IV framework as category E1a. It is defined by the presence of biliary-type pain in a patient with an intact gallbladder, in the absence of gallstones, sludge, microlithiasis, or other structural biliary abnormality, and with normal liver and pancreatic laboratory values documented during pain episodes. FGBD occupies a clinically challenging niche at the intersection of functional gastroenterology, hepatobiliary surgery, and diagnostic imaging, because it involves a symptom pattern (biliary pain) that is traditionally associated with gallstone disease, yet no identifiable stone or structural cause can be found.

The condition has been known by numerous names in the medical literature, including acalculous biliary pain, gallbladder dyskinesia, chronic acalculous cholecystitis, biliary dyskinesia, and acalculous biliary disease. These terms have been used with varying definitions across different medical traditions, contributing to confusion about diagnosis, prognosis, and management. The Rome IV criteria, published in 2016 by the Rome Foundation, sought to bring standardization by defining FGBD using a positive, symptom-based framework that incorporates both a specific biliary pain definition and a set of exclusionary requirements.

FGBD is perhaps the most debated entity within the Rome IV biliary disorders category. The central controversy concerns the role of cholecystectomy: should the gallbladder be removed in patients with typical biliary pain but no stones, and if so, does a low gallbladder ejection fraction on cholescintigraphy predict symptomatic improvement after surgery? These questions remain incompletely resolved, and the Rome IV framework provides the diagnostic scaffolding upon which these clinical decisions are made.

Historical Context and Evolution of the Concept

The concept that the gallbladder could cause pain in the absence of gallstones has a long history. For decades, surgeons observed that some patients undergoing cholecystectomy for presumed biliary symptoms had no gallstones found at surgery or on pathologic examination. Some of these patients improved after surgery, while others did not, raising fundamental questions about whether a "dysfunctional" gallbladder could genuinely cause pain.

The term "gallbladder dyskinesia" gained traction in the 1980s and 1990s with the widespread adoption of cholecystokinin (CCK)-stimulated cholescintigraphy (HIDA scan), which provided a quantitative measure of gallbladder emptying. A low gallbladder ejection fraction (GBEF), typically defined as less than 35% to 40%, was proposed as an indicator of gallbladder motor dysfunction that might explain biliary-type symptoms in the absence of stones. This concept was appealing because it offered an objective, measurable parameter to guide surgical decision-making.

However, the evidence linking low GBEF to symptoms and to surgical outcomes has been inconsistent. Population-based studies have shown that low GBEF is common in asymptomatic individuals, and randomized controlled trials comparing cholecystectomy to sham procedures or medical management in patients with low GBEF and biliary-type pain have produced conflicting results. The Rome III criteria (2006) included gallbladder dyskinesia within the functional gallbladder and sphincter of Oddi disorder framework, and Rome IV refined the diagnostic criteria while explicitly positioning low GBEF as a supportive rather than required criterion.

Rome IV also updated the biliary pain definition to be more precise and clinically discriminating, specifying seven characteristics that collectively define the Rome IV biliary pain phenotype. This was a significant advancement over earlier iterations, which used less granular pain descriptors that overlapped extensively with other causes of epigastric and right upper quadrant pain.

The Rome IV Biliary Pain Definition

The Rome IV criteria for FGBD are built on a two-tier structure. The first tier is the Rome IV biliary pain definition, which describes the characteristic pain pattern. The second tier adds FGBD-specific requirements (intact gallbladder, absence of structural disease, normal labs, chronicity, and exclusion of alternative diagnoses). Both tiers must be fully satisfied.

The Rome IV biliary pain definition requires that the pain meet all of the following seven characteristics:

1. Located in the Epigastrium and/or Right Upper Quadrant

Biliary pain is characteristically located in the epigastric region (upper central abdomen) and/or the right upper quadrant (RUQ). The epigastric location is more common than many clinicians realize; classical teaching that biliary pain is primarily a "RUQ" phenomenon understates the frequency of epigastric or even left upper quadrant radiation. For Rome IV purposes, the pain must involve the epigastrium, the RUQ, or both. Pain localized exclusively to other abdominal regions (e.g., periumbilical, lower quadrants, flank) is not consistent with the biliary pain definition.

2. Builds Up to a Steady Level

Despite the traditional term "biliary colic," biliary pain is not truly colicky (waxing and waning in waves like intestinal or renal colic). Instead, it builds progressively to a plateau of constant, steady intensity, where it remains until the episode resolves. This steady-state character is one of the most important discriminating features of biliary pain. Pain that fluctuates markedly in intensity, comes and goes in brief waves, or is described as crampy or spasmodic is more suggestive of intestinal colic, functional bowel disorders, or other non-biliary etiologies.

3. Lasts 30 Minutes or Longer

Biliary pain episodes are sustained, typically lasting 1 to several hours. The 30-minute minimum threshold is set by Rome IV to exclude brief, transient episodes of epigastric discomfort that are common in the general population and unlikely to represent true biliary pain. Most genuine biliary pain episodes last 1 to 5 hours. Pain lasting less than 15 to 20 minutes is very unlikely to be biliary in origin. Pain lasting more than 5 to 6 hours (particularly if unremitting and escalating) raises concern for acute cholecystitis, choledocholithiasis, or pancreatitis and warrants urgent evaluation.

4. Occurs at Variable Intervals (Not Daily)

Biliary pain episodes recur at irregular, unpredictable intervals. Patients may go days, weeks, or even months between episodes. Daily pain is not characteristic of biliary pain and should prompt consideration of alternative diagnoses such as functional dyspepsia, chronic pancreatitis, peptic ulcer disease, or musculoskeletal pain. This criterion reflects the episodic nature of biliary pain, which is thought to arise from transient gallbladder distension, sphincter spasm, or ductal pressure changes that do not occur on a predictable daily basis.

5. Severe Enough to Interrupt Daily Activities or Lead to an Emergency Department Visit

Biliary pain is characteristically intense. It is not a mild discomfort or a vague ache; it is severe enough to disrupt the patient's normal activities, sometimes prompting an emergency department visit. This severity threshold helps distinguish biliary pain from the mild, chronic, ill-defined upper abdominal discomfort seen in functional dyspepsia and other non-biliary functional disorders. Patients who describe their pain as a minor annoyance or a low-grade background sensation are unlikely to have true biliary pain.

6. Not Significantly Related to Bowel Movements (<20%)

Biliary pain is not meaningfully relieved or exacerbated by bowel movements. The Rome IV threshold specifies that the relationship to defecation should be less than 20% (i.e., the pain does not improve with defecation in more than 20% of episodes). This criterion is designed to distinguish biliary pain from irritable bowel syndrome (IBS), where abdominal pain is, by definition, related to defecation. A patient whose epigastric or RUQ pain is consistently relieved by having a bowel movement is more likely to have IBS than biliary pain.

7. Not Significantly Relieved by Postural Change or Acid Suppression (<20%)

Biliary pain is not meaningfully relieved by changes in body position or by acid-suppressive therapy (antacids, H2-receptor antagonists, proton pump inhibitors). Pain that improves with sitting upright, lying on one side, or with antacid use is more suggestive of gastroesophageal reflux disease (GERD), peptic ulcer disease, or musculoskeletal pain. This criterion helps differentiate biliary pain from the large population of patients with acid-related upper abdominal symptoms that respond to antisecretory therapy.

FGBD-Specific Criteria

Once the Rome IV biliary pain definition is satisfied, the following six additional criteria must all be met for a diagnosis of functional gallbladder disorder:

1. Gallbladder in Situ (Intact, Not Post-Cholecystectomy)

By definition, functional gallbladder disorder applies only when the gallbladder is present. Patients who have undergone cholecystectomy and continue to experience biliary-type pain fall into different Rome IV categories: functional biliary sphincter of Oddi disorder (E2) or functional pancreatic sphincter of Oddi disorder (E3). This distinction is clinically critical because the post-cholecystectomy evaluation and management pathway differs substantially from the pre-cholecystectomy pathway.

2. No Gallstones, Sludge, Microlithiasis, or Other Structural Abnormality

Transabdominal ultrasound is the first-line imaging study for evaluating the gallbladder. It must not show gallstones, biliary sludge, microlithiasis, gallbladder polyps of concern, gallbladder wall thickening suggestive of cholecystitis, or other structural abnormality that explains the symptoms. If transabdominal ultrasound is equivocal, endoscopic ultrasound (EUS) may be performed to evaluate for microlithiasis or small stones missed by standard ultrasound. MRCP (magnetic resonance cholangiopancreatography) may be obtained to evaluate the bile duct and exclude choledocholithiasis or ductal abnormalities.

The exclusion of microlithiasis deserves particular emphasis. Microlithiasis (stones smaller than 3 mm, often below the resolution of standard ultrasound) has been implicated as a cause of "acalculous" biliary pain in some studies. When microlithiasis is identified (by EUS, bile microscopy, or clinical inference), the diagnosis shifts from functional gallbladder disorder to symptomatic microlithiasis, and cholecystectomy may be more clearly indicated.

3. Normal Liver and Pancreatic Laboratory Values During Pain on at Least Two Occasions

This criterion requires that during episodes of pain, the patient's liver tests (AST, ALT, alkaline phosphatase), conjugated (direct) bilirubin, and amylase and/or lipase are all within normal limits. Critically, this must be documented on at least two separate occasions during pain episodes. A single normal set of labs is insufficient because transient elevations during an episode might be missed if labs are drawn only once or only between episodes.

This requirement serves to exclude:

• Choledocholithiasis: Common bile duct stones typically cause transient elevations in liver enzymes and/or bilirubin during pain episodes.
• Acute pancreatitis: Elevated amylase and/or lipase during biliary-type pain indicates pancreatic involvement, not a functional diagnosis.
• Cholangitis: Ascending cholangitis produces liver enzyme and bilirubin elevations along with fever and systemic illness.
• Sphincter of Oddi dysfunction: Transient enzyme elevations during pain in a post-cholecystectomy patient suggest sphincter of Oddi dysfunction rather than FGBD.

The practical implication is that clinicians must instruct patients to present for laboratory testing during or immediately after pain episodes, which can be logistically challenging given the unpredictable timing of biliary pain. Providing patients with laboratory orders and clear instructions to go for blood draws during episodes is an essential step in the diagnostic process.

4. Criteria Fulfilled for the Last 3 Months

Consistent with other Rome IV disorders of gut-brain interaction, the diagnostic criteria must have been met over the preceding 3 months. This ensures that the condition is chronic and not attributable to an acute, self-limited process. A single episode of biliary-type pain, regardless of how characteristic, is insufficient for the diagnosis.

5. Symptom Onset at Least 6 Months Before Diagnosis

The first onset of the qualifying symptoms must have occurred at least 6 months before the diagnosis is applied. This dual temporal gate (3-month fulfillment plus 6-month onset) ensures chronicity and stability, reducing the likelihood of misclassifying an evolving organic process as a functional disorder.

6. Symptoms Not Fully Explained by Another Medical Disorder

After appropriate evaluation, the clinical picture should not be better explained by another condition. This is a broad exclusionary criterion that requires the clinician to consider the full differential diagnosis for episodic epigastric and RUQ pain and to ensure that conditions such as peptic ulcer disease, GERD, chronic pancreatitis, cardiac ischemia, musculoskeletal pain, and functional dyspepsia have been adequately addressed. The diagnosis of FGBD is appropriate only when the biliary pain pattern is present, the gallbladder is intact and structurally normal, labs are normal during episodes, and no better alternative explanation exists.

Supportive Criteria

Rome IV identifies several supportive features that, while not required for diagnosis, lend additional confidence when present:

Low Gallbladder Ejection Fraction on Cholescintigraphy

A gallbladder ejection fraction (GBEF) below conventional cutoffs (typically less than 35% to 40%) on CCK-stimulated hepatobiliary iminodiacetic acid (HIDA) cholescintigraphy supports impaired gallbladder motility and is the most discussed supportive criterion. The role of GBEF in FGBD diagnosis and management is explored in detail in a dedicated section below.

Associated Nausea and Vomiting

Nausea and vomiting frequently accompany biliary pain episodes and are supportive of a biliary etiology. However, nausea and vomiting are nonspecific and occur with many causes of upper abdominal pain, so their absence does not argue against the diagnosis.

Radiation to the Back and/or Right Infrasubscapular Region

Posterior radiation, particularly to the right scapular or interscapular region, is a classic associated feature of biliary pain. When present, it increases clinical confidence in the biliary nature of the pain. However, radiation to the back is also seen in pancreatitis, peptic ulcer disease, and musculoskeletal conditions, so it is supportive but not specific.

Waking the Patient from Sleep

Nocturnal awakening from pain supports a visceral biliary origin and argues against pain that is primarily postural, functional, or related to daytime activities. Pain that consistently occurs only during the day and never at night may warrant additional scrutiny for non-biliary causes.

Epidemiology

The epidemiology of functional gallbladder disorder is difficult to define precisely because the diagnosis requires a specific pattern of pain combined with normal imaging and laboratory results, a workup that is not uniformly applied in population-based surveys. Nevertheless, available data provide useful estimates.

Biliary-type pain in the absence of gallstones (acalculous biliary pain) is estimated to affect 1% to 8% of the general adult population, depending on the criteria used and the population studied. Among patients referred for evaluation of biliary-type symptoms, approximately 5% to 20% have no gallstones or structural biliary disease identified on imaging. These patients constitute the population from which FGBD diagnoses are drawn, although not all will meet the full Rome IV criteria.

Cholecystectomy for acalculous biliary pain (often labeled as "biliary dyskinesia") has become increasingly common in the United States and other Western countries, particularly in the past two decades. Studies of cholecystectomy trends have documented a substantial rise in the proportion of cholecystectomies performed for acalculous indications, particularly in younger women. This trend has generated concern about the possibility of overdiagnosis and overtreament, making the standardized Rome IV criteria all the more important as a diagnostic anchor.

FGBD appears to affect women more frequently than men, consistent with the sex distribution of gallbladder disease in general. The condition is seen across all adult age groups but may be most commonly diagnosed in young to middle-aged women. Psychosocial comorbidity (anxiety, depression, somatization) is more prevalent in FGBD patients than in those with symptomatic gallstones, consistent with the gut-brain interaction model of these disorders.

Pathophysiology

The pathophysiology of functional gallbladder disorder is multifactorial and remains an active area of investigation. Several mechanisms have been proposed:

Gallbladder Dysmotility

Impaired gallbladder contractility is the most widely cited mechanism. The gallbladder normally contracts in response to cholecystokinin (CCK) released from duodenal I-cells following ingestion of fat and protein. This contraction empties bile into the cystic duct and common bile duct for delivery to the duodenum. In FGBD, the gallbladder may contract inadequately, leading to bile stasis, gallbladder distension, and pain.

Cholescintigraphy with CCK stimulation provides a quantitative assessment of gallbladder motor function. A low GBEF (less than 35% to 40%) is interpreted as evidence of gallbladder dysmotility. However, the test has significant limitations: GBEF varies with the rate of CCK infusion, the patient's fasting state, concurrent medications (opioids, calcium channel blockers, anticholinergics, and hormonal contraceptives can all reduce GBEF), body habitus, and day-to-day physiological variation. Reproducibility studies have shown that GBEF can vary by 10% to 20% on repeat testing in the same individual, questioning its reliability as a standalone diagnostic criterion.

Visceral Hypersensitivity

Analogous to the visceral hypersensitivity seen in IBS and functional dyspepsia, some patients with FGBD may have an enhanced perception of normal gallbladder distension, contraction, or bile flow. In this model, the gallbladder itself functions normally (or near-normally), but the sensory pathways transmitting information from the gallbladder to the central nervous system are sensitized, leading to pain perception from stimuli that would be imperceptible in a non-sensitized individual.

This mechanism is consistent with the observation that some FGBD patients have normal GBEF on cholescintigraphy yet experience typical biliary pain. It also aligns with the higher prevalence of psychosocial comorbidity and overlap with other DGBI in this patient population.

Low-Grade Gallbladder Inflammation

Histopathological studies of gallbladders removed from patients with acalculous biliary pain have reported findings including chronic cholecystitis (chronic inflammatory cell infiltration, fibrosis, Rokitansky-Aschoff sinuses), cholesterolosis (cholesterol-laden macrophages in the gallbladder mucosa), and lymphoplasmacytic inflammation. These findings are common in cholecystectomy specimens from FGBD patients, but they are also found incidentally in asymptomatic individuals, making their pathogenic significance uncertain.

Some investigators have proposed that subclinical gallbladder inflammation may sensitize visceral afferents, contributing to both dysmotility and hypersensitivity. This would represent a peripheral mechanism of sensitization analogous to the low-grade mucosal inflammation described in IBS and functional dyspepsia.

Altered Cholecystokinin Signaling

Abnormalities in CCK secretion, CCK receptor expression, or post-receptor signaling in gallbladder smooth muscle have been proposed as contributors to gallbladder dysmotility. Some studies have reported altered CCK-1 receptor density or altered intracellular signaling pathways in gallbladder smooth muscle from FGBD patients, though findings have not been consistently replicated.

Autonomic Dysfunction

The gallbladder receives parasympathetic innervation via the vagus nerve and sympathetic innervation from the celiac plexus. Imbalances in autonomic tone, whether from systemic autonomic dysfunction (as seen in diabetes mellitus) or from central dysregulation related to stress and psychosocial factors, may impair gallbladder motility and modulate visceral pain perception.

Gallbladder Microbiome

Emerging research has explored the bile and gallbladder microbiome in biliary diseases. Alterations in the gallbladder bacterial composition may contribute to low-grade inflammation and altered mucosal signaling. This is a nascent field, and its relevance to FGBD specifically is not yet established.

The Role of Cholescintigraphy and Gallbladder Ejection Fraction

CCK-stimulated cholescintigraphy (HIDA scan) is the most commonly used test to evaluate gallbladder motor function. The study involves intravenous injection of a technetium-99m-labeled hepatobiliary iminodiacetic acid (HIDA) agent, which is taken up by hepatocytes and excreted into bile. After the gallbladder fills with radiolabeled bile, CCK (or its synthetic analogue sincalide) is infused intravenously to stimulate gallbladder contraction. The gallbladder ejection fraction is calculated as the percentage decrease in gallbladder radioactivity over a defined time interval (typically 30 to 60 minutes post-CCK infusion).

A GBEF below 35% to 40% is generally considered abnormal, though the exact cutoff varies across institutions. Some centers use 35%, while others use 38% or 40%. The Society of Nuclear Medicine and Molecular Imaging (SNMMI) practice guidelines recommend standardized sincalide infusion protocols (0.02 mcg/kg infused over 60 minutes) to improve reproducibility.

Limitations of GBEF

Several important limitations affect the clinical utility of GBEF:

• Poor specificity: Low GBEF is found in 15% to 30% of asymptomatic, healthy volunteers. A low GBEF alone does not establish that the gallbladder is the cause of the patient's symptoms.
• Poor reproducibility: GBEF can vary significantly on repeat testing. Factors including CCK infusion rate, duration, dose, patient fasting state, body habitus, and concurrent medications all influence the result.
• Medication effects: Opioids, calcium channel blockers, anticholinergics, progesterone-containing hormonal contraceptives, octreotide, and other drugs can reduce gallbladder contractility and produce falsely low GBEF values. Medication reconciliation and, when feasible, a washout period before testing are essential.
• Inconsistent correlation with surgical outcomes: The relationship between low GBEF and symptom improvement after cholecystectomy has been inconsistent across studies. Some retrospective series report high rates of symptom resolution (80% to 90%) after cholecystectomy in patients with low GBEF and typical biliary pain, while randomized controlled trials have shown more modest and sometimes non-significant benefits.
• CCK reproduction of symptoms: Some clinicians use the reproduction of the patient's typical pain during CCK infusion as an additional criterion (a "positive" CCK provocation test). However, CCK-induced abdominal symptoms are common even in healthy individuals, and the specificity of pain reproduction during the test is debated.

Given these limitations, Rome IV positions low GBEF as a supportive rather than required criterion for FGBD. A patient who meets all Rome IV required criteria but has a normal GBEF still qualifies for the diagnosis. Conversely, a patient with a low GBEF who does not meet the Rome IV biliary pain definition should not be diagnosed with FGBD on the basis of the GBEF alone.

Clinical Evaluation and Differential Diagnosis

The evaluation of a patient with suspected FGBD should be systematic and thorough. Because the diagnosis requires exclusion of numerous organic conditions, a structured workup is essential.

Step 1: Characterize the Pain Pattern

The clinician should systematically assess whether the patient's pain meets all seven Rome IV biliary pain criteria. This requires detailed questioning about location, quality (steady versus colicky), duration, frequency/pattern (episodic at variable intervals, not daily), severity, relationship to bowel movements, and response to postural change and acid suppression. A pain diary in which the patient records episodes, their characteristics, duration, and any relieving or exacerbating factors can be invaluable.

Step 2: Imaging

• Right upper quadrant ultrasound: The first-line imaging study. Evaluates for gallstones, sludge, gallbladder wall thickening, pericholecystic fluid, gallbladder polyps, common bile duct dilation, and hepatic abnormalities. Must be performed fasting (8 to 12 hours) for optimal gallbladder distension.
• Endoscopic ultrasound (EUS): Superior to transabdominal ultrasound for detecting microlithiasis, small stones, bile duct stones, and ampullary or pancreatic pathology. Should be considered when transabdominal ultrasound is negative but clinical suspicion for biliary pathology remains high.
• MRCP: Noninvasive evaluation of the biliary and pancreatic ductal anatomy. Useful for excluding choledocholithiasis, ductal strictures, and anatomic variants.
• CT abdomen: Not the primary imaging modality for gallbladder evaluation (ultrasound is superior for gallstones), but useful for evaluating alternative diagnoses (pancreatitis, renal pathology, retroperitoneal processes, hepatic masses).

Step 3: Laboratory Testing During Pain Episodes

The Rome IV criteria require normal liver tests (AST, ALT, alkaline phosphatase), conjugated bilirubin, and amylase and/or lipase during pain episodes, documented on at least two separate occasions. Patients should be instructed to present for blood work during or immediately after an episode. Abnormal values during episodes redirect the workup toward choledocholithiasis, acute pancreatitis, cholangitis, or sphincter of Oddi dysfunction.

Step 4: Upper Endoscopy

EGD is recommended to exclude peptic ulcer disease, erosive esophagitis, eosinophilic esophagitis, gastric or duodenal malignancy, and celiac disease, all of which can produce epigastric pain that may mimic biliary pain. Biopsies of the gastric antrum (for Helicobacter pylori) and duodenum (for celiac disease) should be obtained when clinically indicated.

Step 5: Consider Cholescintigraphy

CCK-stimulated HIDA scan with GBEF calculation may be performed as a supportive test. As discussed, a low GBEF is supportive of FGBD but not required. A normal GBEF does not exclude the diagnosis.

Step 6: Exclude Non-GI Causes

The differential diagnosis for episodic RUQ and epigastric pain extends beyond the gastrointestinal tract:

• Cardiac: Atypical angina or inferior wall myocardial ischemia can present as epigastric or RUQ pain. ECG and cardiac evaluation should be considered in patients with cardiovascular risk factors.
• Pulmonary: Right lower lobe pneumonia or pleuritis can produce RUQ pain. Chest imaging may be warranted.
• Musculoskeletal: Costochondritis, intercostal neuralgia, rib pathology, and abdominal wall pain (including anterior cutaneous nerve entrapment syndrome) can mimic biliary pain. The Carnett test (point tenderness that worsens with abdominal wall tensing) can help identify abdominal wall sources.
• Renal: Nephrolithiasis or pyelonephritis can cause flank pain radiating to the RUQ.

Key Differential Diagnoses

• Cholelithiasis (gallstones): The most common organic cause of biliary pain. Excluded by ultrasound (and EUS if ultrasound is negative but suspicion remains).
• Choledocholithiasis: Common bile duct stones may cause biliary pain with transient liver enzyme elevations. Excluded by normal episode-related labs and imaging (MRCP, EUS).
• Functional dyspepsia: Postprandial fullness, early satiation, and epigastric pain/burning may overlap with biliary pain. However, functional dyspepsia pain does not typically build to a steady plateau, does not last 30+ minutes per episode, and may respond to acid suppression. Careful symptom characterization helps distinguish the two, though overlap is possible.
• Irritable bowel syndrome (IBS): Epigastric or RUQ pain in IBS is characteristically related to bowel movements (a distinguishing feature from biliary pain per Rome IV criterion 6).
• Peptic ulcer disease: Gnawing or burning epigastric pain that may respond to antacids and food. Excluded by EGD.
• Chronic pancreatitis: Epigastric pain radiating to the back, often worsened by eating and alcohol. Excluded by imaging (CT, MRCP, EUS) and pancreatic function testing.
• Sphincter of Oddi dysfunction: In the setting of post-cholecystectomy biliary pain. Not applicable when the gallbladder is intact (Rome IV categories E2/E3 apply post-cholecystectomy).
• GERD: Epigastric burning or pain that improves with acid suppression (criterion 7 helps exclude).

The Cholecystectomy Debate

The most consequential clinical question in FGBD is whether cholecystectomy provides lasting symptom relief. This question has generated intense debate, and the available evidence is mixed.

Evidence Favoring Cholecystectomy

Numerous retrospective case series have reported symptom improvement rates of 70% to 90% after cholecystectomy in patients with biliary-type pain, no gallstones, and low GBEF. These studies have been influential in driving the widespread adoption of cholecystectomy for "biliary dyskinesia." Histopathological examination of removed gallbladders frequently reveals chronic cholecystitis, cholesterolosis, or other inflammatory changes, which has been interpreted as evidence that the gallbladder was indeed pathologic.

Evidence Questioning Cholecystectomy

Retrospective studies are subject to selection bias and placebo effects. The few randomized controlled trials (RCTs) that have addressed this question have produced more nuanced results. Some RCTs have shown a modest benefit of cholecystectomy over conservative management, while others have shown no significant difference. A key challenge is that the placebo effect of surgery is substantial; patients who undergo cholecystectomy may report improvement simply because they believe the source of their pain has been removed.

Furthermore, studies following patients after cholecystectomy for acalculous biliary pain have reported that 20% to 40% of patients continue to have similar pain after surgery, suggesting that the gallbladder was not the true source in a significant minority. When these patients then undergo evaluation for persistent pain, the diagnoses that emerge include functional dyspepsia, IBS, sphincter of Oddi dysfunction, and persistent functional biliary pain, suggesting that the original presentation may have been a functional gastrointestinal disorder rather than a gallbladder-specific problem.

Current Approach

Most current guidelines recommend an individualized approach. Cholecystectomy may be considered in patients who meet the full Rome IV criteria for FGBD, particularly when a low GBEF is documented, when the pain is severe and recurrent, when medical management has failed, and when the patient has been thoroughly counseled about the uncertain benefit of surgery. The patient should understand that cholecystectomy provides lasting relief in a proportion of cases but not all, and that persistent symptoms after surgery are a recognized possibility.

Shared decision-making between the patient and a multidisciplinary team (gastroenterologist, surgeon, and sometimes a psychologist familiar with DGBI) is essential. Patients with prominent psychosocial comorbidity, overlap with other DGBI (IBS, functional dyspepsia), or pain that does not strictly conform to the Rome IV biliary pain definition may be less likely to benefit from surgery.

Management Strategies

Conservative and Medical Management

Before proceeding to cholecystectomy, a trial of medical management is often appropriate:

• Reassurance and education: Explaining the diagnosis, the benign nature of the condition, and the concept of gut-brain interaction can reduce anxiety and may itself improve symptoms.
• Dietary modifications: Avoiding high-fat meals (which are the strongest stimulus for CCK release and gallbladder contraction) may reduce the frequency and severity of episodes. A low-fat diet is a reasonable first-line intervention.
• Antispasmodics: Hyoscyamine, dicyclomine, or other smooth muscle relaxants may provide acute relief during episodes by reducing gallbladder and biliary tract smooth muscle spasm. Evidence is limited, but they are commonly used empirically.
• Neuromodulators: Low-dose tricyclic antidepressants (amitriptyline, nortriptyline, imipramine at 10 to 50 mg nightly) may reduce visceral hypersensitivity and central pain processing, addressing the gut-brain interaction component. SSRIs or SNRIs may be considered in patients with concurrent anxiety or depression.
• NSAIDs: Indomethacin and other NSAIDs have been shown to reduce gallbladder inflammation and may abort acute biliary pain episodes. However, long-term NSAID use carries gastrointestinal and cardiovascular risks.
• Ursodeoxycholic acid (UDCA): Has been used in some patients with FGBD, based on its ability to reduce bile lithogenicity and its potential anti-inflammatory and cytoprotective effects on the gallbladder mucosa. Evidence for efficacy in FGBD specifically is limited.

Psychological Therapies

Given the gut-brain interaction nature of FGBD, psychological therapies may play an important role:

• Cognitive behavioral therapy (CBT): Can address catastrophizing, hypervigilance, and maladaptive coping strategies related to pain.
• Gut-directed hypnotherapy: Has demonstrated efficacy in other DGBI and may be applicable to functional biliary pain.
• Stress management and relaxation techniques: Chronic stress and autonomic dysregulation may contribute to gallbladder dysmotility and visceral hypersensitivity.

Cholecystectomy

Laparoscopic cholecystectomy is the definitive surgical option for FGBD. As discussed, it should be considered when medical management has failed, when the Rome IV criteria are fully met, when a supportive low GBEF has been documented (though not required), and when the patient has been informed of the uncertain but potentially favorable probability of lasting symptom improvement. Cholecystectomy is generally a safe procedure with low complication rates, but as with any surgery, it carries risks including bile duct injury, bleeding, infection, and post-cholecystectomy diarrhea (reported in 10% to 20% of patients due to altered bile acid metabolism).

Using the Rome IV Functional Gallbladder Disorder Calculator

The Rome IV Functional Gallbladder Disorder diagnostic criteria calculator is a clinical decision-support tool designed to systematically evaluate whether a patient meets the Rome IV criteria for FGBD (E1a). The calculator is organized into two groups of criteria:

Biliary Pain Criteria (7 items):

1. Pain located in the epigastrium and/or right upper quadrant.
2. Pain builds up to a steady level.
3. Pain lasts 30 minutes or longer.
4. Pain occurs at variable intervals (not daily).
5. Pain is severe enough to interrupt daily activities or lead to an ED visit.
6. Pain is not significantly (<20%) related to bowel movements.
7. Pain is not significantly (<20%) relieved by postural change or acid suppression.

FGBD-Specific Criteria (6 items):

1. Gallbladder in situ (not post-cholecystectomy).
2. No gallstones, sludge, microlithiasis, or structural abnormality on imaging.
3. Normal liver and pancreatic laboratory values during pain on at least two occasions.
4. Criteria fulfilled for the last 3 months.
5. Symptom onset at least 6 months before diagnosis.
6. Symptoms not fully explained by another medical disorder.

All 13 required elements must be affirmed for a positive result. The calculator also provides an intermediate result when the biliary pain definition is met but the FGBD-specific criteria are incomplete, guiding the clinician to pursue further workup. If the biliary pain criteria themselves are not fully met, the calculator indicates that the pain pattern does not conform to the Rome IV biliary pain definition and suggests alternative diagnoses.

Supportive criteria (low GBEF, nausea/vomiting, back/scapular radiation, nocturnal awakening) are presented for reference but do not affect the required criteria assessment. This tool is intended for educational and clinical decision-support purposes and does not replace comprehensive clinical evaluation or the judgment of a qualified healthcare provider.

Overlap with Other Functional Biliary and GI Disorders

FGBD exists within a spectrum of functional biliary and gastrointestinal disorders. The Rome IV biliary disorders category (E) includes:

• E1a: Functional gallbladder disorder (the subject of this article)
• E1b: Functional biliary sphincter of Oddi disorder (biliary-type pain in a post-cholecystectomy patient without structural biliary abnormality)
• E2: Functional pancreatic sphincter of Oddi disorder (pancreatic-type pain in a post-cholecystectomy patient without structural pancreatic abnormality)

The relationship between FGBD and post-cholecystectomy functional biliary pain is of particular clinical importance. Some patients who undergo cholecystectomy for FGBD and continue to have pain may subsequently be diagnosed with functional biliary sphincter of Oddi disorder (E1b), raising the question of whether the gallbladder was the true source of pain in the first place or whether the underlying process was always a sphincter or central sensitization problem.

FGBD also overlaps with functional dyspepsia (B1), particularly the epigastric pain syndrome (EPS) subtype. Both conditions feature episodic epigastric pain, and the distinction rests on the specific characteristics of the Rome IV biliary pain definition (steady plateau, minimum 30-minute duration, variable intervals, severity, and lack of relationship to bowel movements, posture, or acid suppression). Some patients may meet criteria for both conditions, and treatment may need to address both.

Overlap with IBS is possible but should be carefully distinguished by the Rome IV biliary pain criterion requiring that pain is not significantly related to bowel movements. Patients with predominant pain-bowel movement relationships are more appropriately classified as having IBS.

Prognosis and Long-Term Outlook

The long-term prognosis of FGBD is variable and depends in part on the management approach. Patients who undergo cholecystectomy and experience symptom relief generally have a favorable outcome. Those who do not improve after surgery, or who are managed conservatively, may have a chronic, fluctuating course similar to other DGBI.

FGBD does not carry an increased risk of gallbladder cancer, biliary tract malignancy, or progression to gallstone disease. Some patients with FGBD may eventually develop gallstones over time (as can anyone in the general population), which would reclassify their condition.

Quality of life can be significantly impaired during episodes, given the severity of biliary pain and its unpredictability. Between episodes, patients are typically asymptomatic. Addressing the psychosocial dimensions of the illness, providing clear diagnostic communication, and developing a shared management plan can improve the patient's sense of control and overall well-being.

Longitudinal follow-up is recommended, as some patients with an initial presentation consistent with FGBD may develop new findings on repeat imaging or laboratory testing that redirect the diagnosis. Similarly, patients whose symptoms evolve to include daily pain, weight loss, jaundice, or other alarm features should be promptly re-evaluated.