Irritable Bowel Syndrome (IBS) Health Center

Medical and dietary history

To determine whether your symptoms meet the criteria for diagnosing irritable bowel syndrome (IBS), your doctor may ask you questions about:

• Recent stressful events in your life. Stress may be a strong indication that your symptoms may be caused by irritable bowel syndrome.
• Bowel function, including how many bowel movements you have per day or per week, whether you have constipation or diarrhea, whether you have noticed any blood or mucus in your stool, and any recent changes in your bowel habits or the shape of your stools.
• Whether your bowel movement patterns have any relationship to your abdominal pain (for example, if passing a stool relieves the pain and cramping).
• Family history of similar symptoms.
• Family relationships that may be causing stress.
• Your use of laxatives or antacids.
• Factors that may increase your risk of an intestinal infection, such as foreign travel, drinking untreated water, or recent antibiotic use.

The dietary history will include questions about food allergies and whether your symptoms seem to be related to any particular foods. Foods that most commonly cause symptoms include lactose (milk sugar) and sorbitol, an artificial sweetener found in sugarless chewing gum and other sugar-free products.

The doctor may suggest that for a period of time you try avoiding foods that seem to cause problems, to see if your symptoms get better.

Physical exam

To help determine whether you have irritable bowel syndrome, the doctor will perform a standard physical examination, including:

• Feeling the abdomen.
• A digital rectal exam.
• Listening for bowel sounds (with a stethoscope).
• A routine pelvic exam (in women).

Why It Is Done

A medical history and physical examination are standard tests for people who have abdominal pain and changes in bowel habits.

Results

Key findings in IBS are abdominal pain that is relieved with a bowel movement and a change in the consistency or number of times per day or week that you have bowel movements. The pain is not limited to one part of the abdomen. It may move around and may come and go. It often occurs or gets worse when you eat. Stress may also be related to abdominal pain.

The abdomen may be swollen if you have gas in the intestines. Your abdomen may be tender when the doctor presses on it. Abnormal bowel sounds may be heard, especially, but not only, if you have diarrhea. You may report symptoms such as an urgent need to have bowel movements or a feeling that you haven't completely emptied the bowel after passing a stool.

A person who has IBS may have constipation more often, diarrhea more often, or constipation that alternates with diarrhea.

All other physical findings should be normal for a diagnosis of IBS.

What To Think About

Because there is no detectable structural problem that causes IBS, if you have a normal physical exam but you do have symptoms of IBS, this strongly suggests that you have irritable bowel syndrome. If your doctor thinks your symptoms may be caused by another problem, he or she may recommend other tests, such as:

• Blood tests (complete blood count [CBC] and/or sedimentation rate), to rule out anemia, inflammation, or infection.
• Test for blood in the stool (fecal occult blood test), to check for bleeding in the intestinal tract or white blood cells in the stool (a sign of inflammation or infection in the intestines).
• Tests for parasites in the stool, to check whether a parasitic infection, such as giardiasis, is causing symptoms.
• Thyroid and liver function tests, to check for metabolic problems.
• A blood test to rule out celiac disease.

Your doctor may recommend other tests not in this list. But if there are no symptoms (such as anemia, rectal bleeding or bloody diarrhea, fever, weight loss, pain that wakes you at night, or recent change in bowel habits) that suggest other intestinal diseases, few additional tests are needed. If these symptoms are present, tests for other problems, such as inflammatory bowel disease or an ulcer, may be needed.

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