People with irritable bowel syndrome may be able to find some relief by getting regular exercise, a small clinical trial suggests.

The study, of 102 adults with the disorder, found that those who were told to get some more exercise had better odds of seeing improvements in problems like cramps, bloating, constipation and diarrhea.

After three months, 43 percent of the exercisers showed a "clinically significant" improvement in their symptoms - meaning it was making a difference in their daily lives. That compared with a quarter of the participants who maintained their normal lifestyle.

For people who are currently less-than-active, even a moderate increase in exercise may curb irritable bowel symptoms, according to senior researcher Dr. Riadh Sadik, of the University of Gothenburg in Sweden.

In an email, Sadik said the researchers had told those in the exercise group to get 20 to 60 minutes of moderate-to-vigorous exercise - like brisk walking or biking - on three to five days out of the week.

That's a level that is generally safe and achievable, Sadik said. On top of that, the researcher added, "it will also improve your general health."

About 15 percent of Americans have irritable bowel syndrome, or IBS, which causes bouts of abdominal cramps, bloating and diarrhea or constipation.

It is different from inflammatory bowel disease, which includes two digestive diseases - ulcerative colitis and Crohn's disease - that are believed to involve an abnormal immune system reaction in the intestines.

The exact cause of IBS is unknown, but people with the condition often find that they have certain symptom "triggers," such as particular foods, larger-than-normal meals or emotional stress.

The typical treatment includes diet changes, as well as anti-diarrheal medication and, for constipation, laxatives or fiber supplements. There's also some evidence that behavioral therapy and stress-reduction tactics help some people.

According to Sadik, exercise may be helpful for several reasons. Past studies have shown that it can get things moving along in the gut, relieving gas and constipation. (Vigorous exercise, however, may worsen bouts of diarrhea.)

Regular exercise may also have a positive influence on the nervous and hormonal systems that act on the digestive tract.

None of the participants in the new study, reported in the American Journal of Gastroenterology, were regularly active at the outset. The researchers randomly asked about half to begin exercising over a 12-week period, with advice from a physical therapist. The rest stuck with their normal lifestyle habits.

At the end of the study, the exercise group reported greater improvements on a standard questionnaire on IBS symptoms. They were also less likely to show worsening symptoms.

Of the exercise group, 8 percent had a clinically significant increase in IBS symptoms, versus 23 percent of the comparison group.