The term "irritable bowel syndrome," or IBS, describes a group of symptoms that occur together. These symptoms include discomfort or pain in the belly (abdomen) and changes in the way the bowels move, either constipation or diarrhea. Some people have both constipation AND diarrhea, just at different times.

Diagnosing IBS

Making the Diagnosis

There are no tests that identify IBS (like blood tests, x-rays, scopes, or scans). Instead, in IBS, typical symptoms form a pattern that is used to diagnose the condition (called symptom-based criteria).

A doctor will start by asking about symptoms and health history, and then do a physical exam and limited tests. Your doctor may suggest a blood test to check for Celiac disease if you are experiencing diarrhea or diarrhea and constipation (a positive test should be confirmed by a biopsy). Unless there are "warning" signs this is generally all that is needed to diagnose IBS.

Warning signs and symptoms

Warning signs are simply certain signs and symptoms that are not typical of IBS. Other diseases can have symptoms similar to IBS, but they also have special features that set them apart from IBS. The doctor may want to run extra tests if you have any of the following:

• anemia and other abnormal blood tests,
• blood in the stool,
• unexplained weight loss,
• fever, or
• a family history of inflammatory bowel disease or other diseases of the colon

IBS signs and symptoms

The typical signs and symptoms of IBS are:

• pain or discomfort in the belly (abdomen),
• that happens several days or more per month over at least the last 3 months, and
• is related to changes in the way your bowel moves

What is meant by 'related to changes in the way your bowel moves'? Typically, it means having 2 out of the following 3:

• the pain/discomfort gets better after a bowel movement
• bowel movements that are more often or less often
• stools that are getting harder or softer

Other common symptoms

The signs and symptoms listed above are distinguishing features of IBS. But other symptoms are also often felt by persons with IBS - digestive symptoms such as

• Bloating
• Heartburn
• Early feeling of fullness
• Nausea
• Upper belly discomfort or pain that comes and goes (dyspepsia)
• Feelings of urgency (the need to find a restroom fast)
• Passage of mucus in the stool
• Feeling of "incomplete" bowel emptying

And symptoms that don't seem related to the digestive tract such as

• Fatigue
• Muscle pain
• Sleep disturbances
• Sexual dysfunction
• Low back pain
• Headache

Tests

If you have the typical symptoms of IBS, and your doctor says "Your tests are negative" it means that you don't have some other disease. Tests look for other things, not for IBS.

At this point your doctor might also say something like, "Based on your symptoms and exam, you have IBS." Your signs and symptoms fit the standard for diagnosing IBS. The next step is to learn all you can about IBS and work with your doctor on a treatment plan that fits you.

If, on the other hand, your doctor says, "Your tests are negative" and insists that "Nothing is wrong with you" despite all the symptoms you have, then think about talking to another doctor.

Not all doctors understand disorders like IBS. They may be trained to look only for visible evidence of a problem, such as signs of infection or injury - things they can see on an x-ray, scope or other test. But IBS is a problem with the way a system works; there is no visible evidence that shows up on a test. That's not the same thing as "nothing is wrong." People have painful headaches, but nothing shows up on tests. It's the same with IBS.

What if you have a test result that is positive? It may be a minor problem. You may have something else along with your IBS, or you may have something else entirely. A doctor will help you sort this out.

Remember

A doctor familiar with IBS will likely be able to make a diagnosis based on your symptoms, a physical exam, and few basic tests to rule out something else. Once you have a diagnosis you can start finding ways to best manage and treat your IBS.

Find more in-depth information about diagnosing IBS here.