What is the most common cause of diarrhea after cholecystectomy (gallbladder removal)?

From the Guidelines

The most common cause of diarrhea after gallbladder removal is bile acid malabsorption, also known as bile acid diarrhea. This condition occurs when the gallbladder is removed, and bile flows continuously into the small intestine, overwhelming its capacity to reabsorb bile acids, allowing excess bile acids to reach the colon. In the colon, these bile acids stimulate electrolyte and water secretion and increase colonic motility, resulting in diarrhea. This condition affects approximately 10-20% of patients following gallbladder removal, as reported in studies such as the one by the Canadian Association of Gastroenterology 1.

Key Points

• Bile acid malabsorption is a common cause of diarrhea after cholecystectomy
• The condition is characterized by the continuous flow of bile acids into the small intestine, overwhelming its capacity to reabsorb them
• Excess bile acids reach the colon, stimulating electrolyte and water secretion and increasing colonic motility, resulting in diarrhea
• Management typically includes dietary modifications and bile acid sequestrants like cholestyramine, colestipol, or colesevelam, as suggested by the British Society of Gastroenterology 1

Management

• Dietary modifications, such as reducing fat intake, can help alleviate symptoms
• Bile acid sequestrants, such as cholestyramine (4-8g taken 2-3 times daily before meals), colestipol, or colesevelam, can bind to bile acids in the intestine, preventing their irritant effect on the colon
• Patients should start with a low dose and gradually increase as needed to minimize side effects like bloating and constipation
• Antidiarrheal medications, such as loperamide, may also provide symptomatic relief, as noted in the guidelines for the investigation of chronic diarrhoea in adults 1

Diagnosis

• Diagnosis can be made using tests such as the 75 selenium homocholic acid taurine (SeHCAT) scan or measurement of serum bile acid precursors, such as 7α-hydroxy-4-cholesten-3-one, as discussed in the guidelines for the management of bile acid diarrhea 1
• Faecal bile acid measurement can also be used, but it requires a 48-hour sample and is not yet commercially available in some countries, as mentioned in the guidelines for the investigation of chronic diarrhoea in adults 1

From the Research

Causes of Diarrhea after Gallbladder Removal

• The most common cause of diarrhea after cholecystectomy (gallbladder removal) is bile acid malabsorption (BAM) 2, 3, 4.
• Bile acid malabsorption occurs when the bile acids are not properly absorbed in the small intestine, leading to chronic diarrhea 2, 4.
• The prevalence of bile acid malabsorption in patients with chronic watery diarrhea and previous cholecystectomy is estimated to be around 70% 4.

Diagnosis and Treatment of Bile Acid Malabsorption

• The diagnosis of bile acid malabsorption can be made using the SeHCAT test, which measures the absorption of bile acids in the small intestine 2, 4.
• Treatment of bile acid malabsorption typically involves the use of bile acid sequestrants, such as cholestyramine, which bind to bile acids in the intestine and prevent their absorption 2, 3, 5.
• Cholestyramine has been shown to be effective in reducing symptoms of diarrhea in patients with bile acid malabsorption, with a response rate of around 79% 4.

Other Causes of Diarrhea after Gallbladder Removal

• Other causes of diarrhea after gallbladder removal may include extra-biliary conditions, such as irritable bowel syndrome, functional diarrhea, and Crohn's disease 6, 3.
• These conditions may require different treatment approaches, and a thorough evaluation is necessary to determine the underlying cause of diarrhea in patients who have undergone cholecystectomy 6, 3.