Introduction Background Diarrhoea is a common presenting complaint in the Gastroenterology outpatient department. The potential causes are numerous, but include irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), coeliac disease, and colorectal cancer. Interest in bile acid malabsorption (BAM) as a cause of diarrhoea has increased recently. However, guidelines from the British Society of Gastroenterology do not recommend routine exclusion of this condition using 23-seleno-25-homo-tauro-cholic acid (SeHCAT) scanning.
Methods Review of consecutive unselected new patient referrals to a single Gastroenterologists’ outpatient clinic during a 2-year period, from January 2010 to December 2011. All clinic letters were reviewed retrospectively, and symptoms reported by the patient at the initial consultation were recorded. Radiology, endoscopy, chemical pathology, and histopathology databases were then cross-examined in order to ascertain the final diagnosis following full investigation, to the level deemed appropriate by the consulting physician. We defined BAM using a SeHCAT retention value of < 15% at 7 days.
Results Of 397 consecutive unselected new patient referrals to a single Gastroenterologist between January 2010 and December 2011, 102 (25.7%) reported diarrhoea. After investigation the final diagnoses are listed in Table 1. The second commonest cause of diarrhoea, after IBS, was BAM. Eight (53.3%) of 15 patients with BAM reported lower abdominal pain or discomfort. In 10 (66.7%) patients there was no obvious cause of BAM, and these were classified as idiopathic, or type II, BAM.
Conclusion BAM was the commonest underlying cause of diarrhoea after IBS. Idiopathic BAM was commoner than coeliac disease. More than 50% of patients with BAM reported lower abdominal pain or discomfort, which may lead to misdiagnosis as IBS unless further investigations are performed. BAM should be considered as a likely diagnosis in all patients with diarrhoea, and SeHCAT scanning should be moved up the hierarchy of diagnostic tests in such patients.
Disclosure of Interest None Declared