Skip to main content

A primer on irritable bowel syndrome

Irritable bowel syndrome (IBS) is a digestive disorder that may affect up to 15 percent of Americans.

For some people, the symptoms of IBS are mild. But others experience excruciating pain, chronic diarrhea or constipation, knifelike cramping, and other symptoms that force them to abandon travel, work and social events.

Even though it's one of the most common gastrointestinal illnesses that doctors see, no two cases are alike, which makes treatment particularly tricky.

And IBS produces no telltale signs of disease—no x-ray or blood test that proves what’s going on. In fact, doctors diagnose IBS by eliminating other problems first and documenting symptoms that eventually add up to IBS.

What IBS is not

According to the American College of Gastroenterology, IBS may be best defined by what it isn't:

  • It isn't cancer, and it doesn't cause cancer.
  • It’s not life-threatening.
  • It doesn't progress to a more serious disorder, such as inflammatory bowel disease.
  • It doesn't cause other gastrointestinal diseases.
  • It isn't an anatomical or structural defect in the intestines or body.

What IBS is

Theories abound about what causes IBS, but nobody yet knows for sure. For whatever reason, people with IBS have bowels that don't work correctly and that are extra sensitive to food and stress.

Symptoms usually appear first in adolescence or early adulthood, rarely after 50. They may come and go or be constant.

Doctors look for abdominal pain or discomfort that lasts for 12 weeks—not necessarily consecutive weeks—during the past year. According to the American Medical Association, other signs and symptoms include:

  • Bloating and gas, particularly after eating.
  • Abdominal pain relieved by having a bowel movement.
  • Urgency to have a bowel movement, sometimes right after having one.
  • A change in appearance of bowel movements.
  • Diarrhea or constipation, or both.

Treating IBS requires trial and error

Finding the right combination of treatment will take patience and time. Most people control symptoms by:

Making dietary changes. It may help to cut back on or eliminate foods that seem to provoke IBS, such as milk products and foods that cause gas. Adding more fiber and making sure to drink enough water may also help.

Taking medicine. Common IBS medications include antispasmodics to decrease spasms in the bowels, antidepressants to reduce pain, laxatives to treat constipation, and antidiarrheals to reduce stool frequency and diarrhea.

Reducing stress. Stress doesn't cause IBS, but it can aggravate its symptoms. Exercise or counseling can help control stress.

Taking the long view

Nearly all people with IBS can be helped, even if their illness can't be cured. The first step is getting a careful evaluation from a doctor.

Then, the secret is learning what works—and what doesn't—for you.

reviewed 12/4/2018

Related stories