KU Leuven researchers have traced the cause of abdominal pain in patients with irritable bowel syndrome (IBS). They also found out which compound could reduce or eliminate pain. It is the same substance as is in an existing medicine for hay fever.
IBS patients have intestines that are exceptionally sensitive, similar to a skin that is very sensitive to sunburn. Thus far, the origin of the hypersensitivity remained unknown. Researchers knew that the intestines of patients with IBS contain large amounts of the substance, histamine, but a concrete link with the hypersensitivity was not established yet.
The team of Professor and gastroenterologist Guy Boeckxstaens could now demonstrate that histamine has an effect on the pain receptor TRPV1. Histamine acts on the histamine-1 receptor, which is located on nerves that activate TRPV1. Large amounts of histamine provide an overstimulation of TRPV1. That explains the pain experienced by patients with IBS.
Based on these findings, the researchers looked for a solution to the problem. They found a substance that blocks the histamine-1 receptor on the nerve, so that the sensitivity of TRPV1 is no longer increased. This substance is ebastine, a substance that is already used in hay fever medication. Patients who were treated for twelve weeks with ebastine had significantly less abdominal pain compared with patients in the control group. In a follow-up study, the effect of ebastine will be tested on two hundred IBS patients.
Irritable bowel syndrome is a condition that affects ten to fifteen percent of the population. The present treatment is aimed at the normalization of bowel movements, but it cannot reduce or eliminate the pain. The results of this study may change that.