Bile Acid Malabsorption Flashcards
Bile Acid Malabsorption
Bile-acid malabsorption
Bile-acid malabsorption is a cause of chronic diarrhoea. This may be primary, due to an excessive production of bile acid, or secondary to an underlying gastrointestinal disorder causing reduced bile acid absorption. 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
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 75SeHCAT
Management
bile acid sequestrants e.g. cholestyramine
Bile Acid Malabsorption - Example Question
A 36-year-old man attends gastroenterology clinic with an 8-month history of watery diarrhoea. He opens his bowels up to 15 times a day and this is not associated with any rectal bleeding. His symptoms are not relieved by loperamide. He has a history of Crohn’s disease which was diagnosed 5 years ago and had an ileal resection 12 months ago following an inflammatory stricture. He does not smoke and drinks approximately 35 units of alcohol a week. His medications include omeprazole 20mg OD, paracetamol 1g QDS and ibuprofen 400mg TDS PRN.
His blood tests are: Hb 115 g/l Na+ 139 mmol/l Bilirubin 12 µmol/l Platelets 395 * 109/l K+ 3.9 mmol/l ALP 100 u/l WBC 10.5 * 109/l Urea 6.5 mmol/l ALT 42 u/l Neuts 5.5 * 109/l Creatinine 100 µmol/l γGT 65 u/l CRP 4 mg/L Albumin 37 g/l Amylase 124 U/L
Which investigation is most likely to confirm the diagnosis?
Faecal elastase CT abdomen Faecal calprotectin Secretin stimulation test > SeHCAT test
Bile acid malabsorption can occur in patients with Crohn’s disease affecting the ileum or following ileal resection. Bile salts are mostly absorbed in the ileum and the inability to do so results in chronic diarrhoea. Treatment with bile acid sequestrants such as cholestyramine is often effective. SeHCAT test is a form of nuclear imaging test which is used to investigate patients suspected of having bile acid malabsorption.
Bile Acid Malabsorption and Chronic Diarrhoea
Bile acid malabsorption can occur in patients with Crohn’s disease affecting the ileum or following ileal resection. Bile salts are mostly absorbed in the ileum and the inability to do so results in chronic diarrhoea. Treatment with bile acid sequestrants such as cholestyramine is often effective. SeHCAT test is a form of nuclear imaging test which is used to investigate patients suspected of having bile acid malabsorption.
