IRRITABLE BOWEL SYNDROME, or IBS, is a disorder that affects the large intestine. It causes abdominal pain and cramping along with diarrhea, constipation or a combination of both. IBS is not the same as inflammatory bowel disease.

It is not clear why IBS develops. It can occur after a bacterial or parasitic infection of the intestines such as giardiasis. This is called post-infectious IBS. Other triggers may include stress. Hormone and nerve signals that travel between the intestines and the brain affect bowel function. The nerves can become more active during stress, causing the intestines to be more sensitive and contract more.

About 10–15 percent of people in the United States have IBS symptoms. It can occur at any age but often begins in the teen years or early adulthood and is twice as common in women as in men. It is less likely to begin after age 50. You are likely to have IBS if you have a family history of the syndrome or have a behavioral health issue such as anxiety, depression or a history of abuse. It is the most common intestinal problem referring people to a gastroenterologist.

IBS symptoms vary from person to person, ranging from mild to severe; most people have mild symptoms. You have IBS when symptoms are present for at least three days a month for a period of three months or more. Main symptoms include abdominal pain, gas, fullness, bloating and change in bowel habits. Pain and other symptoms are often reduced or go away after a bowel movement. Symptoms may flare up when there is a change in the frequency of your bowel movements.

If you have IBS with diarrhea, you will have frequent, loose, watery stools. You may have an urgent need to have a bowel movement which may be hard to control. If you have IBS with constipation, you will have a hard time passing stool as well as fewer bowel movements. You may need to strain and have cramps. Often, only a small amount or no stool at all will pass.

Symptoms may get worse for a few weeks or a month and then decrease for a while. In other cases, symptoms are present most of the time. You may also lose your appetite if you have IBS. However, blood in stools and unintentional weight loss are not a part of IBS.

There is no test to diagnose IBS. Usually your health care provider can diagnose IBS based on your symptoms. Eating a lactose-free diet for two weeks may help identify lactase deficiency (lactose intolerance). Blood tests can determine if you have celiac disease or anemia, and a stool culture can check for infection.

Your provider may recommend a colonoscopy. During this test, a flexible tube is inserted through the anus to examine the colon. You may need this test if symptoms began later in life (over age 50), if you have weight loss or bloody stools, or if you have abnormal blood tests such as a low blood count. Other disorders that can cause similar symptoms include celiac disease, Crohn’s disease, ulcerative colitis and colon cancer. However, cancer rarely causes typical IBS symptoms unless weight loss, blood in the stools or abnormal blood tests are also present.

The goal of treatment is to relieve symptoms. In some cases, lifestyle changes help. Regular exercise and improved sleep habits may reduce anxiety and help relieve bowel symptoms. Dietary changes can also help. However, no specific diet can be recommended for IBS because the condition differs from one person to another. Avoid foods and drinks that stimulate the intestines, such as caffeine. Eat smaller meals. Increase fiber in the diet. This may improve constipation or diarrhea but make bloating worse.

Talk with your provider before taking over-the-counter medicines. No one medicine works for everyone. These medications may include anticholinergic medicines (dicyclomine, propantheline, belladonna and hyoscyamine), taken a half-hour before eating to control intestinal muscle spasms; Bisacodyl laxative to treat constipation; and Loperamide to treat diarrhea. Some patients take low doses of tricyclic antidepressants to help relieve intestinal pain, Lubiprostone for constipation or the antibiotic Rifaximin.

Psychological therapy or medicines for anxiety or depression may help with IBS. Finding ways to deal with stress, such as individual or group counseling, biofeedback, progressive relaxation exercises and mindfulness training, can help to prevent or ease symptoms. Complementary health practices such as hypnosis, probiotics, peppermint oil, herbal remedies and acupuncture may have benefits.

The content of this article is for informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition.