Experts estimate that upwards of 20% of the population in the U.S. suffers from Irritable Bowel Syndrome (IBS), which is characterized by abdominal discomfort, bloating, constipation, and/or diarrhea. Researchers have recently made some strides in exploring the underpinnings of IBS, which include changes to the bacteria of the gut and in the wiring of the brain itself. Still, IBS presents a puzzle to researchers – not to mention its sufferers – and effective treatments for the syndrome have been elusive, at best.

The exercise group reported significant improvement in their symptoms compared to the control group: exercisers reported an average 51-point drop in symptoms severity, vs. just a 5-point drop in the control group.

A recent study shows that exercise may just do the trick. The researchers behind the current study split a small pool of 75 IBS sufferers into two groups: one group was asked to exercise moderately-to-vigorously for 20-60 minutes 3-5 times per week. The control group was asked simply to continue their usual routines. The participants all filled out extensive questionnaires on type and severity of their symptoms, as well as how dissatisfied they were with their bowel habits and how much their IBS interfered with their lives. The surveys were filled out at the beginning of the study and again after three months.

The exercise group reported significant improvement in their symptoms compared to the control group: exercisers reported an average 51-point drop in symptoms severity, vs. just a 5-point drop in the control group. Additionally, significantly more people in the control group reported that their symptoms worsened over the three months than people in the exercise group. Exercise also produced other beneficial effects: People in the exercise group reported greater improvements in quality of life issues, like energy, sleep, and emotional well-being, than the control group.

The authors suggest that exercise may be a powerful (not to mention easy and cheap) way to manage IBS symptoms. But why does exercise help IBS in the first place? The authors suggest a few mechanisms may be at play. First, exercise seems to counteract the effects of stress by inhibiting certain stress hormones, which seem to play a role in the severity of IBS. Similarly, exercise may boost the brain’s ability to adapt and regenerate, which could affect the brain-gut connection that seems to be so central in IBS.

The authors do point out that there’s probably some degree of placebo effect in these results. It is impossible to design a "blinded" study when it comes to exercise in particular (since it's clear who is on a specific exercise regimen and who isn't), and any treatment that the participants are aware they are receiving is bound to help in some way.

Still, exercise does seem to offer some very real, physiological effects, with several viable theories to explain the connection. More research is currently underway both to get at the causes and to develop new treatments for IBS. In the meantime, if you’re an IBS sufferer, it might be fun to do your own experiment and add a little exercise to your routine — just to see if it works for you.

The study was carried out by a team at the University of Gothenburg and published in the January 4, 2011 issue of the American Journal of Gastroenterology. It can be accessed here.