Bile acid malabsorption in microscopic colitis and in previously unexplained functional chronic diarrhea

Area of Science:

• Gastroenterology
• Internal Medicine
• Clinical Research

Background:

• Bile acid malabsorption (BAM) is documented in collagenous colitis but not lymphocytic colitis.
• The relationship between BAM and microscopic colitis (MC) requires further investigation.
• The potential for concomitant occurrence of BAM and MC, rather than BAM being integral to MC, is unexplored.

Purpose of the Study:

• To determine the prevalence and severity of BAM in MC and functional chronic diarrhea (FCD).
• To evaluate the efficacy of cholestyramine in inducing and maintaining remission for these conditions.
• To explore the association between BAM and MC, and idiopathic BAM.

Main Methods:

• [75Se]HCAT retention tests were conducted on 26 collagenous colitis, 25 lymphocytic colitis, and 32 FCD patients.
• Treatment with cholestyramine was administered to MC patients with BAM, a subgroup of MC without BAM, and all FCD patients with BAM.

Main Results:

• BAM was present in 43.1% of MC patients and 75% of FCD patients.
• BAM was significantly more frequent in lymphocytic colitis (60%) than collagenous colitis (27%).
• Cholestyramine induced remission in 19/22 MC patients with BAM, 0/8 MC patients without BAM, and all FCD patients with BAM.

Conclusions:

• Bile acid malabsorption is a frequent finding in microscopic colitis, particularly lymphocytic colitis, and in functional chronic diarrhea.
• Microscopic colitis and bile acid malabsorption often occur concurrently.
• Cholestyramine demonstrates high efficacy in resolving diarrhea associated with BAM in these patient groups.