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Bile Acid Malabsorption (BAM)

Bile Acid Malabsorption or Diarrhoea (BAM) is a cause of chronic diarrhoea with the patients having their bowels open several times a day. There can be number of reasons why patients get this condition and these have been placed in to three types:

  • Type 1: Bile acid malabsorption, secondary to ileal resection, or ileal inflammation - Crohn’s disease, ileal resections
  • Type 2: Idiopathic / primary bile acid malabsorption
  • Type 3: Secondary to various gastrointestinal diseases – Cholecystectomy, small intestinal bacterial overgrowth, post radiation, coeliac disease, chronic pancreatitis

Bile salts are made in your liver (see diagram). When you eat a meal, especially if it has fat in it, these bile salts are released from your liver and gall bladder (if you still have one) into your upper intestine (duodenum). They help to digest the food as it travels through your small bowel. When the bile salts reach the far end of your small bowel, they are mostly absorbed back into your body and travel back in the blood stream to your liver. They are stored here until they are needed for the next meal

There is one specific area of the small bowel which is responsible for absorbing these bile salts. If this area becomes diseased or has been removed at surgery or damaged, for example by radiotherapy, it may not be possible for enough of the bile salts to be absorbed back into your body. If, as a result of failed absorption, too much bile salt reaches your lower intestine (colon), bile salt will cause fluid to be pumped into your colon by your body, which will cause diarrhoea (loose or watery stools).