The most common irritable bowel syndrome (IBS) symptoms—abdominal pain, flatulence, diarrhea, bloating, or constipation—are the uncomfortable and inconvenient gastrointestinal (GI) complaints that bring many patients to their doctor, says Steven Lamm, MD, author of No Guts, No Glory (Basic Health Publications, 2012). But very few patients actually meet the criteria for IBS.

"A lot of people go to the doctor complaining about chronic constipation, chronic diarrhea or alternating constipation and diarrhea, for which there is no diagnosis made," says the GI expert adding that more often than not, a milder, more transient bowel disorder is diagnosed.

The difficulty in diagnosing IBS lies in the absence of physical changes in the body. IBS is considered a functional GI disorder that doesn't damage the GI tract. It affects the large intestine (colon)—but not permanently—by impeding how well the GI tract works. Inflammatory bowel disease (IBD), on the other hand, is an autoimmune condition that damages the digestive system and raises cancer risk.

"We don't want to diminish IBS, we just want to differentiate it from a condition that is much-better defined pathologically," says Lamm. You can see the damage that is caused by IBD. Not so, with IBS. IBS does not cause inflammation or changes in bowel tissue. Ulcerative colitis and Crohn's disease are more serious digestive disorders that would have pathology associated with them.

But that doesn't mean IBS is not a serious condition. 

IBS can be truly incapacitating and contribute to quality of life issues. See your doctor if you have the following symptoms:

  • Bloating
  • Abdominal pain
  • Changes in bowel habits
  • Diarrhea and/or constipation
  • Feeling that a bowel movement is incomplete
  • Passing mucus

Criteria for Diagnosing IBS

According the National Institutes of Health, IBS is diagnosed when a person has abdominal pain or discomfort at least three times per month for the last three months without other disease or injury that could explain the pain. The pain or discomfort of IBS may occur with a change in stool frequency or consistency or may be relieved by a bowel movement.

Additionally, it is often classified into four subtypes:

  1. IBS with constipation
  2. IBA with diarrhea
  3. Mixed IBS
  4. Un-subtyped IBS

Your doctor will complete a physical exam and review your medical history, including symptoms, family history, recent infections, medications, and mental health.

Once a physical exam and blood tests rule other conditions out, a combination of therapies are usually prescribed, says Lamm. They include:

  • Lifestyle changes, such as diet and exercise
  • Stress management techniques
  • Medications (laxatives, antidiarrheals, antidepressants, etc.) to alleviate symptoms
  • Enzymes and probiotic regime to support healthy gut flora
  • Mental health therapies to combat anxiety and depression

In many cases, IBS can be controlled by with simple lifestyle changes as well as learning to manage diet and stress.

Steven Lamm, MD, reviewed this article.


Steven Lamm, MD, "House Doctor" on ABC's The View and author of No Guts, No Glory (Basic Health Publications, 2012)

Irritable Bowel Syndrome. National Digestive Diseases Information Clearinghouse (NDDIC). Web. July 2012.