Cholestyramine for Bile Acid Diarrhea

Primary Indication and Efficacy

The Canadian Association of Gastroenterology recommends cholestyramine as the initial therapy for confirmed or suspected bile acid diarrhea, based on systematic evidence review 1, 2
Cholestyramine is effective in 88% of patients with post-cholecystectomy diarrhea and confirmed bile acid malabsorption, at doses of 2-12 g/day 1
Approximately 28% of patients with chronic diarrhea and clinical suspicion of bile acid diarrhea respond to cholestyramine 3

Consider cholestyramine in patients with terminal ileal resection or disease, post-cholecystectomy diarrhea, post-radiation enteritis, irritable bowel syndrome with diarrhea, and unexplained chronic diarrhea 1, 3, 4
Start with cholestyramine 4 g once or twice daily with meals, then titrate up to 2-12 g/day based on symptom response, with the goal of using the lowest effective dose 1, 4

Approximately 39-94% of patients experience recurrent diarrhea when cholestyramine is withdrawn, depending on the underlying cause and severity 1
Prolonged use of cholestyramine can cause malabsorption of vitamins A, D, E, and K, with vitamin D deficiency occurring in 20% of patients 4
Monitor for decreased serum bicarbonate and elevated serum chloride to prevent hyperchloremic metabolic acidosis, particularly in patients with pre-existing renal impairment or volume depletion 7

If cholestyramine is ineffective or poorly tolerated, consider alternative agents like colesevelam, loperamide, or hydroxypropyl cellulose 1, 4
The Canadian Association of Gastroenterology suggests diagnostic testing, such as SeHCAT or 7α-hydroxy-4-cholesten-3-one, over empiric therapy when available, to predict response to cholestyramine 2, 3