Bile-acid malabsorption is a cause of chronic diarrhoea. This may be primary, due to excessive production of bile acid, or secondary to an underlying gastrointestinal disorder causing reduced bile acid absorption. It can lead to steatorrhoea and vitamin A, D, E, K malabsorption.

Secondary causes are often seen in patients with ileal disease, such as with Crohn's. Other secondary causes include:

• cholecystectomy
• coeliac disease
• small intestinal bacterial overgrowth
• post infective gastroenteritis
• post-cholecyctectomy

Investigation

• the test of choice is SeHCAT
• nuclear medicine test using a gamma-emitting selenium molecule in selenium homocholic acid taurine or tauroselcholic acid (SeHCAT)
• scans are done 7 days apart to assess the retention/loss of radiolabelled SeHCAT

Management

• bile acid sequestrants e.g. cholestyramine