Irritable bowel syndrome—also known as spastic colon, mucous colitis, nervous bowel, or simply IBS—is a common abdominal complain. While IBS is not a disease, it's probably the least understood but most common reason for visits to gastroenterologists.

IBS usually develops in late adolescence or early adulthood and affects three times as many women as men. It’s estimated that 10 to 15 percent of the adult population in the United States has IBS to some degree, but only about half seek medical attention. Irritable bowel syndrome is also a major cause of absenteeism from work.

IBS does not require surgery, is not caused by any known physical abnormality, and is not the same thing as inflammatory bowel disease—a serious disorder that may produce ulceration of the intestinal wall. Irritable bowel syndrome is a chronic disorder that is more difficult to cope with than the occasional bout of diarrhea or nervous stomach most people experience from time to time.

IBS is linked with digestion. After partly digested food leaves the stomach, it is moved along through the small and large intestine by a gentle synchronized wavelike contraction and relaxation (peristalsis) of the intestinal wall muscles. In IBS sufferers, the muscles go into spasm for unknown reasons, causing residue to move either too quickly (causing diarrhea) or too slowly (leading to constipation).

IBS does not cause fever or bleeding. Gastrointestinal problems like diarrhea may mysteriously give way to constipation, and sufferers usually also have abdominal pain and a lot of gas. The condition may correct itself and then return suddenly—often before an important occasion about which you already feel tense.

Symptoms of Irritable Bowel Syndrome

Symptoms vary from person to person and are often triggered by a particular food, stressful event, or bout of depression. The most common symptoms include:

  • Moderate to severe abdominal cramps, nausea, pain, gas, belching and bloating (Pain is often relieved by a bowel movement.)
  • Constipation or diarrhea, sometimes bouts of both lasting for days, weeks or months (Diarrhea may occur immediately after awakening in the morning or right after eating and may contain white mucus.)
  • Feeling that the bowels have not completely emptied or a continual urge to defecate
  • Straining with bowel movements or inability to have a bowel movement
  • Hard / lumpy stools or watery or very loose stools
  • More than three bowel movements every day
  • Loss of appetite
  • Swollen or bloated abdomen
  • Fecal incontinence
  • A worsening of symptoms after eating a big meal, during menstrual periods, or when you are under stress.

What Causes Irritable Bowel Syndrome?

No one is sure what causes IBS. Some doctors attribute it to an as-yet-undetermined physiological disorder, and emotional stress and anxiety are certainly associated with it—although there is no evidence that irritable bowel syndrome itself is a psychological disorder. Rather, stress, anxiety, and/or depression may be a result of having the disease. Research is being conducted to investigate the possibility of a lower pain threshold for people with IBS, which then triggers the disorder.

Certain foods may cause sudden flare-ups. Common triggers include high-fat foods, such as bacon, vegetable oils, and margarine, as well as gas-producing foods like beans and broccoli. Lactose intolerance—the inability to digest lactose (milk sugar), caused by an enzyme deficiency—can also produce the same symptoms.

What If You Do Nothing?

It’s estimated that half of the people with IBS don’t seek medical attention and choose instead to live with their “nervous stomach” because their IBS symptoms aren’t that bothersome.

Although the disorder can cause much discomfort, it does not lead to serious disease. If you can learn to control the chronic flare-ups and relieve the often bothersome symptoms of IBS yourself, you can probably keep the condition from interfering with your everyday activities.

Home Remedies for Irritable Bowel Syndrome

The challenge of irritable bowel syndrome comes in trying to treat symptoms without having a clear idea of the causes. IBS usually responds to one or a combination of self-care measures, but it may take some time and trial-and-error to notice results. Depending on your specific symptoms, your doctor can suggest a number of treatments that may help.

  • Watch your diet. Though no food or category of foods is a known or even suspected culprit, there’s no harm in watching your diet, because certain foods may make your symptoms worse. Keep a food diary and if certain foods seem to set off symptoms, try avoiding them for a while. Don’t eliminate them unless they cause problems more than once.
  • Add fiber. A high-fiber diet (fruits, vegetables, and whole grains, taken with plenty of fluids) is known to promote normal bowel function as well as to reduce bloating and other symptoms of IBS. Some people find that the constipation of IBS can be managed by including wheat or oat bran in their daily diet. But bran may not work for some people, and in others it can actually worsen symptoms. If you try bran, start with one teaspoon daily, and slowly increase the amount—up to 9 or 10 teaspoons spread over the course of the day. Be sure to drink plenty of water any time you consume bran.
  • Eat smaller, more frequent meals. Four to six smaller meals eaten throughout the day may be easier to digest than three large ones.
  • Try eliminating gas-forming foods. If your predominant symptom is gas, eliminating beans, peas, lentils, broccoli, cauliflower, onions, cucumbers, and leafy vegetables may help. If symptoms improve, gradually reintroduce these foods and see what happens.
  • Don’t delay. If you feel the urge to move your bowels, do so. Any delay may contribute to becoming constipated.
  • Exercise regularly. This can help reduce stress, stimulate the digestive process, and relieve symptoms.
  • Avoid sorbitol. This artificial sweetener found in candy, gum, and other sugarless products may cause diarrhea.
  • Don’t abuse laxatives. You may become dependent on them and this can eventually weaken your intestines.
  • Don’t assume that you’re lactose-intolerant. Many people with IBS diagnose themselves as lactose-intolerant and stop eating dairy products. But in fact, lactose intolerance doesn’t put you at increased risk for IBS. In any case, it’s easy to find out if you are lactose-intolerant with a simple breath test ordered by your doctor.
  • Reduce daily stress. If you think psychological problems or emotional stress are the chief cause of your symptoms, try relaxation techniques like yoga or meditation. Exercise may also help. You may benefit from talking with a counselor. Or you and your doctor may decide to try antidepressants.

IBS Prevention

There is no known way to prevent irritable bowel syndrome. Nonetheless, by learning how to minimize occasional episodes of IBS with modifications in your diet and with stress management, you may help reduce incidences of the ailment.

Beyond Home Remedies: When To Call Your Doctor

If you frequently suffer from the symptoms of irritable bowel syndrome and they interfere with your normal activities, you should make an appointment with your doctor. A physician can also check for more serious disorders such as gallstones, diverticular disorders, bowel diseases like colon cancer, and ulcers. Your doctor will also want to make sure you are not suffering from bacterial or other infections. Some medication you are taking could also be the culprit.

What Your Doctor Will Do

A detailed patient history will be taken, and a physical examination will be performed. A stool sample may be required to eliminate the possibility of a more serious ailment or infection. A sigmoidoscopy may also be performed. For this procedure a slender, flexible, lighted telescope is inserted into the colon to check the walls of the bowel and rule out inflammatory bowel disease. If necessary, a barium enema or colonoscopy will be performed to further examine your colon.

Once other ailments are precluded and IBS is suspected, your doctor may quiz you about your diet and advise against certain foods. For painful attacks, medications may be prescribed that address the major symptoms: for example, sedatives can help calm anxiety, antidiarrheal medication may be helpful for watery stool, bulk laxatives (high in fiber) can relieve constipation, and antispasmodic drugs may be recommended to reduce the pain of cramping. There are also drugs that partially block the parasympathetic nervous system to decrease cramping; Robinul and Bentyl are the two most commonly prescribed for this purpose. When it comes to treatment, though, irritable bowel syndrome is poorly understood, and the therapies available are not known to have lasting success.


The Complete Home Wellness Handbook

John Edward Swartzberg, M.D., F.A.C.P., Sheldon Margen, M.D., and the editors of the UC Berkeley Wellness Letter

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at

Published: 06 Nov 2011

Last Modified: 22 Sep 2015