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 75SeHCAT test, a faecal fat excretion test and registration of symptoms in addition to the standard clinical work-up.
Methods: The correlation between the 75SeHCAT 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 75SeHCAT value < 10%. Mild steatorrhoea was common in patients with non-organic bile acid malabsorption (50%) and in patients with functional diarrhoea (38%). There was no correlation between low 75SeHCAT 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 75SeHCAT 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 non-organic bile acid malabsorption and functional diarrhoea. The 75SeHCAT 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 75SeHCAT test should be performed early in the investigation of these patients.