New study finds hormone deficiency may cause chronic diarrhea

NEW YORK A common type of chronic diarrhea may be caused by a hormone deficiency, according to new research published in the November issue of Clinical Gastroenterology and Hepatology.

Chronic idiopathic bile acid diarrhea occurs when an overload of bile acid reaches the colon and causes excess water to be secreted into the bowel. The researchers in the study found that a hormone, FGF19, which normally switches off bile acid production in the liver, does not function properly.

The researchers tested the amount of bile acid being produced in the livers of 17 patients diagnosed with bile acid diarrhea and 19 healthy controls. They did this by measuring the amount of a molecule called C4 in the blood, which indicates how much bile acid is being made. The results showed that the people with bile acid diarrhea were producing an average of nearly three times more bile acid than the controls, with 51 nanograms of C4 per mL of blood in the patient group, compared to 18 nanograms per mL in the control group.

"Bile acid diarrhea is a common condition, likely to affect more people than Crohn's disease or ulcerative colitis, yet until now we did not understand exactly what causes it," said lead study author Julian Walters, from the Division of Medicine at Imperial College London. "Our new findings mean that in the future doctors may be able to diagnose the condition by doing a quick and simple blood test."

These results suggest that there is a significant link between bile acid production and decreased levels of FGF19 in people with bile acid diarrhea. The researchers say that, following this small study, further research is needed to see if these findings can be replicated.