Solving the Mystery of IBS

Irritable Bowel Syndrome (IBS) is a mystery disease. Or not a disease. A syndrome, after all, is technically a collection of symptoms grouped together by hope and desperation more than logic. Maybe one thing causes them. Maybe not.

With IBS, the causes are many and deeply disputed. At least doctors (good ones, at any rate) have stopped telling patients it's all about stress. Researchers are pretty sure than someone real is going wrong deep inside the digestive tract.

There is also a disease called Inflammatory Bowel Disease (IBD) which, despite the name and the similarity of symptoms, was thought not to be the same thing as IBS. That might be wrong as well.

The British science magazine The New Scientist had a small article on a research study on IBS, "Getting to the bottom of irritable bowels, by Ken Boroom in their 13 April 2008 issue.

In the article, Boroom talks about an article, "Role for protease activity in visceral pain in irritable bowel syndrome", by Nicolas Cenac. It's from the Journal of Clinical Investigation 117(3): 636-647 (2007). doi:10.1172/JCI29255.

That issue was published on Feb. 15, 2007. The New Scientist is a weekly magazine that normally gives the latest breaking news. Why did they wait over a year to report this? Probably it took Boroom a year to figure out what the heck the report says. It would me.

To take his word for it, there is some really important news buried in the jargon.

You see, people with IBS can have seemingly contradictory symptoms. Some have diarrhea; some have constipation. So far researchers hadn't come up with a common link for both sets of symptoms. Cenac's group has.

They found increased activity of a group of enzymes called serine proteases in all the IBS patients and at double the levels of healthy patients. Not just that, IBD patients also had raised protease activity.

Activity in this case means that a receptor called PAR2, found on nerve cells, epithelial cells, and smooth muscle cells, is activated. Boroom wrote:

If these cells are being overstimulated in IBS patients, it may explain why they complain of widespread pain and hypersensitivity as well as abdominal symptoms.

The natural next step is to look for a protease inhibitor. And in fact one is in trials in Japan as a treatment for IBS, with what Boroom called "promising results."

Many people with IBS also have lactose intolerance (LI). I'm one of them. It's never been clear exactly what the relationship between LI and IBS might be exactly, but it's a major problem for the LI community. A way to stamp out IBS would go a long way toward treating what is probably an underlying condition in the unusual level of suffering that people with LI get that really can't be explained by LI reactions alone.

Good news, even if tangible results are probably still years away.