Researchers at Heidelberg University Hospital say that they have uncovered a molecular basis for an underestimated disease called irritable bowel syndrome (IBS), one of the most common disorders of the gastrointestinal tract.
Writing about their findings in the journal Human Molecular Genetics, the researchers said that their study improves the outlook for an effective medication against the disease that is frequently played down as a functional disorder.
Constipation, others from severe diarrhoea, or a combination of both are some of the symptoms of IBS, the illness affects the general condition and quality of life of these patients and often lasts for months or even years.
"We have determined that patients who suffer from irritable bowel syndrome with diarrhoea show a higher frequency of certain mutations," says Dr. Beate Niesler, who investigates the genetic causes of complex diseases with her team in the Department of Human Molecular Genetics at the Heidelberg Institute of Human Genetics.
The researchers say that these mutations appear to cause changes in the composition or number of receptors on the cell surface.
"The signal transduction in the digestive tract may be disturbed and this may lead to overstimulation of the intestine. Resulting disturbances in fluid balance could explain the occurrence of diarrhoea", says Johannes Kapeller, a PhD student in the team.
The serotonin receptor blocker Alosetron is only approved in the US for the treatment of women suffering from diarrhoea-predominant IBS, but can only be prescribed with strict limitations due to its side effects. Alosetron inhibits the serotonin receptors in the intestinal tract, and thus slows the movement of the bowels.
The researchers say that their findings may lead to development and prescription of specific medications for certain genetic mutations in patients with IBS, who are currently treated on a "trial and error basis".