Should I have tests for irritable bowel syndrome (IBS)?

Introduction

This information will help you understand your choices, whether you share in the decision-making process or rely on your doctor's recommendation.

Key points in making your decision

There are no tests that can definitively diagnose irritable bowel syndrome (IBS). Instead, experts have developed a set of criteria, called the Rome III criteria, that help your doctor decide whether you may have IBS. Your doctor will likely ask you a lot of questions about your symptoms and see how well your symptoms match these criteria. Consider the following when making your decision:

• If you have IBS, test results will be normal.
• An abnormal test result may mean you have a problem other than IBS.
• If your tests are all normal and your symptoms match the symptom criteria common in people with IBS, you probably do not have a serious disorder. You and your doctor can then focus on managing your symptoms so that they do not interfere with your life.
• In general, weigh the likelihood that you may have a more serious problem against the risks, discomfort, and costs of more testing. Testing is the only way to be completely certain that you do not have a more serious problem, but if your symptoms match the criteria for IBS and your doctor is confident that you do not have a more serious problem, further testing is probably not necessary.

Medical Information

What is irritable bowel syndrome (IBS)?

Irritable bowel syndrome (IBS) is a common digestive problem. Many people have symptoms of IBS (such as diarrhea, constipation, bloating, or abdominal pain) and never see a doctor about them. Other people may choose to see a doctor because they are concerned about their symptoms or because the symptoms are affecting their life.

The goal of managing IBS is to improve your quality of life by reducing the symptoms. However, even with good treatment, you may still have some symptoms. Doctors do not fully understand all the factors that may cause IBS. They know that IBS does not lead to other, more serious problems. However, some people may have both IBS and another digestive disorder.

What can tests for other digestive system disorders show?

In general, if you have IBS, all of your test results will be normal. If your symptoms match those of other people who have IBS, you and your doctor may feel confident about the diagnosis.

The tests your doctor may do depend in part on your most bothersome symptoms. For example, diarrhea may be a symptom of infection with a parasite, such as giardiasis. If you have diarrhea, your doctor may do a stool analysis to check for this kind of problem. Or celiac disease may be the cause of your diarrhea. The doctor also may do a flexible sigmoidoscopy or colonoscopy to look at the mucous lining of the colon and may take a sample of the lining to check for inflammation (colitis).

If you have an abnormal test result, it may mean you have a problem other than IBS. You also may have both IBS and another problem.

• Blood tests can show signs that you may have another illness or infection.
• Stool analysis can show infection with bacteria or parasites (such as giardiasis).
• A test for blood in the stool may show blood, which means there may be inflammation or bleeding in some part of the digestive tract.
• Tests for lactose intolerance, which may include a breath test or trial of a lactose-free diet, may show that you have trouble digesting lactose. For more information, see the topic Lactose Intolerance.
• Tests for celiac disease may include a blood test or upper gastrointestinal endoscopy and biopsy. These tests may show that you have trouble digesting gluten (which is found in foods like bread and pasta). For more information, see the topic Celiac Disease.
• Imaging tests such as sigmoidoscopy, colonoscopy, or a barium enema may show problems in the colon such as inflammatory bowel disease, colon polyps, or diverticulosis.

Depending on your age and history and your doctor's preferences for testing for bowel problems, these tests may be recommended at your first visit for symptoms of IBS.

What can you do with the information you get from these tests?

If your tests are all normal and your symptoms match the symptom criteria common in people with IBS, you may feel reassured that you do not have a serious disorder. You and your doctor can then focus on managing your symptoms so that they do not interfere with your life.

In general, consider the likelihood that you may have a more serious problem compared with the risks, discomfort, and costs of more testing. If your symptoms match the criteria for IBS and your doctor feels confident that you do not have a more serious problem, more testing is probably not necessary.

What new problems could develop if you have tests?

Most tests have some risks, although the likelihood of a serious complication caused by testing is low. Some of the tests, such as flexible sigmoidoscopy or colonoscopy, may be uncomfortable. In fact, people with IBS may find flexible sigmoidoscopy more uncomfortable than do people who do not have this disorder.

What are the risks of not having tests?

There is generally little risk in not having tests for other possible causes of symptoms if your symptoms match those of IBS. The symptom criteria for diagnosing this condition can help doctors distinguish between people who have IBS and people who have other problems. The more of these symptoms that are present, the more likely it is that you have IBS.

If you have a more serious problem, your symptoms often will become worse. The presence of "alarm symptoms" also may indicate a more serious problem. Alarm symptoms include fever, unexplained weight loss, blood in your stools, anemia, or a family history of colon cancer or inflammatory bowel disease. Additional tests will usually be recommended in either case.

If you need more information, see the topic Irritable Bowel Syndrome (IBS).

Your Information

This information will be helpful if you have symptoms that your doctor believes are caused by irritable bowel syndrome. Your doctor may have done some tests, such as blood tests and a stool analysis, and now you are considering whether to have an image test, such as a flexible sigmoidoscopy, barium enema, or colonoscopy.

This information may not apply to you if:

• You are over age 50.
• You have blood or pus in your stool.
• Your symptoms have come on quickly over the past few weeks to months.
• You have had unexplained weight loss, fever, or diarrhea at night.
• Your pain wakes you up at night.

In these situations, your doctor will generally want to do more tests to rule out a possibly more serious problem.

In general, your choices are:

• Accept a diagnosis of irritable bowel syndrome. Try treatment for your most bothersome symptom. Reassess your symptoms in several weeks. If they are improving, you and your doctor may feel reassured that you have IBS rather than another problem.
• Have more tests to rule out a more serious problem.

Doctors have different ways of working with people who have symptoms of irritable bowel syndrome. No single approach is correct in all situations.

The decision about whether to have tests for irritable bowel syndrome takes into account your personal feelings and the medical facts.

These personal stories may help you make your decision.

Wise Health Decision

Use this worksheet to help you make your decision. After completing the worksheet, you should have a better idea of how you feel about having tests for irritable bowel syndrome. Discuss the worksheet with your doctor.

Circle the answer that best applies to you.

*NA = Not applicable

Use the following space to list any other important concerns you have about this decision.

What is your overall impression?

Your answers in the above worksheet are meant to give you a general idea of where you stand on this decision. You may have one overriding reason to have or not have tests done for irritable bowel syndrome (IBS).

Check the box below that represents your overall impression about your decision.

Return to the topic Irritable Bowel Syndrome (IBS).

References

Citations

1. Longstreth GF, et al. (2006). Irritable bowel syndrome section of Functional bowel disorders. In DA Drossman et al., eds., Rome III: The Functional Gastrointestinal Disorders, 3rd ed., pp. 490-509. McLean, VA: Degnon Associates.