Ileal malabsorption in adults with Crohn disease

Extensive ileal disease (especially in patients who have undergone ileal resection) may cause bile salt malabsorption. This, in turn, can lead to bile salt diarrhoea (due to the stimulatory effect of bile salts on the colonic mucosa) or to steatorrhoea (due to bile salt depletion)—these may occur in the absence of active inflammation. It is important to distinguish between bile salt diarrhoea, steatorrhoea and active Crohn disease to ensure appropriate management.

In patients with bile salt diarrhoea, colestyramine can reduce symptoms by binding the bile salt. Use:

All other drugs should be taken at least 1 hour before, or 4 to 6 hours after colestyramine.

Adults with significant ileal malabsorption should be managed as for Short bowel syndrome. In particular, such patients require long-term intramuscular vitamin B₁₂ supplementation, Intravenous iron supplementation and fat-soluble vitamin supplementation.

If disease of the small intestine is complicated by bacterial overgrowth, antibiotic therapy may be beneficial—see Small intestinal bacterial overgrowth.

For patients with an ileostomy or colostomy, management should involve a stomal therapist and an accredited practising dietitian.