From the Guidelines
For chronic diarrhea with negative stool testing and normal gallbladder evaluation, I recommend considering bile acid diarrhea (BAD) as a possible diagnosis, and testing using 75 selenium homocholic acid taurine (SeHCAT) or 7a-hydroxy-4-cholesten-3-one, as suggested by the Canadian Association of Gastroenterology 1. When evaluating a patient with chronic diarrhea, it is essential to consider the patient's medical history, including previous surgeries, such as cholecystectomy or terminal ileal resection, which can increase the risk of bile acid diarrhea 1. Some key points to consider in the management of chronic diarrhea include:
- Identifying risk factors for bile acid diarrhea, such as terminal ileal resection or cholecystectomy 1
- Testing for bile acid diarrhea using SeHCAT or 7a-hydroxy-4-cholesten-3-one, rather than empiric bile acid sequestrant therapy (BAST) 1
- Considering other potential causes of chronic diarrhea, such as irritable bowel syndrome (IBS), functional diarrhea, or microscopic colitis 1
- Managing symptoms with dietary modifications, such as a low-FODMAP diet, and medications like loperamide or psyllium fiber supplements, as needed 1
- Monitoring for warning signs, such as weight loss, blood in stool, or nighttime symptoms, which may indicate a more serious underlying condition 1
From the Research
Chronic Diarrhea Diagnosis and Treatment
- Chronic diarrhea is a common problem affecting up to 5% of the population at a given time, with patients experiencing loose stool consistency, increased frequency, urgency of bowel movements, or incontinence as key symptoms 2.
- The diagnosis of chronic diarrhea involves assessing symptom clusters and settings to determine the likelihood of particular causes, with irritable bowel syndrome (IBS) being distinguishable from other causes by the presence of pain that peaks before defecation, is relieved by defecation, and is associated with changes in stool form or frequency (Rome criteria) 2.
- Testing, including blood and stool tests, endoscopy, imaging studies, histology, and physiological testing, is indicated when alarm features are present, when there is no obvious cause evident, or the differential diagnosis needs further delineation 2.
Treatment Options for Chronic Diarrhea
- Pharmacologic agents for chronic diarrhea include loperamide, 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists, diosmectite, cholestyramine, probiotics, antispasmodics, rifaximin, and anti-inflammatory agents 3.
- Loperamide, a synthetic opiate agonist, decreases peristaltic activity and inhibits secretion, resulting in the reduction of fluid and electrolyte loss and an increase in stool consistency, and is considered effective in the treatment of chronic diarrhea 3, 4.
- Cholestyramine is a bile acid sequestrant that is generally considered as the first-line treatment for bile acid diarrhea, and may be relevant in cases where gallbladder testing is normal but chronic diarrhea persists 3.
Considerations for Patients with Negative Stool Testing and Normal Gallbladder Testing
- In patients with chronic diarrhea and negative stool testing, further evaluation may be necessary to determine the underlying cause of symptoms, including assessment of dietary and medication-related factors 2.
- Normal gallbladder testing does not rule out the possibility of bile acid diarrhea, and further testing or empiric treatment with cholestyramine may be considered in some cases 3.