Impact of bile acid malabsorption on steatorrhoea and symptoms in patients with chronic diarrhoea

Objective Bile acids are important for fat absorption. The relationship between bile acid malabsorption and steatorrhoea and gastrointestinal symptoms in patients with chronic diarrhoea has only been studied on a limited scale. Design Ninety-four patients referred for chronic diarrhoea were prospectively investigated with the (75)SeHCAT test, a faecal fat excretion test and registration of symptoms in addition to the standard clinical work-up. Methods The correlation between the (75)SeHCAT value and the faecal fat excretion was calculated for different groups of patients. Symptoms were registered in a questionnaire over a period of seven consecutive days. Results Forty-two patients had a (75)SeHCAT value <10%. Mild steatorrhoea was common in patients with nonorganic bile acid malabsorption (50%) and in patients with functional diarrhoea (38%). There was no correlation between low (75)SeHCAT values and steatorrhoea, although some patients with severe organic disease had a concomitant malabsorption of fat and of bile acids. In coeliac disease, severe steatorrhoea was common even in patients with high (75)SeHCAT values. Patients with bile acid malabsorption had more frequent (P < 0.008) and looser (P = 0.0021) stools compared with patients with functional diarrhoea. There was no difference in abdominal pain, distension or flatulence. Conclusion Mild steatorrhoea is common in both nonorganic bile acid malabsorption and functional diarrhoea. The (75)SeHCAT value cannot predict the risk of steatorrhoea. The high prevalence of bile acid malabsorption in patients with chronic diarrhoea and the absence of specific symptoms, except frequent and more liquid stools, indicates that the (75)SeHCAT test should be performed early in the investigation of these patients. (C) 2000 Lippincott Williams & Wilkins.