Irritable Bowel Syndrome Facts

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Irritable bowel syndrome (IBS) is a common intestinal disorder that leads to cramping, gassiness, bloating, and changes in bowel habits. IBS affects more than 15% of Americans, most of them women, and tends to occur more often in people with stressful and emotionally trying lives.

Triggers of IBS

Other factors can trigger symptoms such as certain medicines and foods. Chocolate, milk products, caffeine, beans, cabbage, and certain fruits may lead to symptoms. Fats in any form (saturated or unsaturated) and large amounts of alcohol can also trigger symptoms. IBS can be brought on by infections in the gastrointestinal tract and hormonal influences. Increased estrogen seems to affect bowel activity, and symptoms can worsen during menstruation.

Symptoms can occur from a few times a week to once a month. IBS can also go away for months or years and suddenly return. Symptoms may get worse for a person under stress from traveling or during a change in daily routine. They also may get worse if you have an unhealthy diet or after you eat a big meal. Keeping a diary of what you eat and your symptoms for a few weeks can help you determine if a certain food bothers you.

There isn't a screening test for IBS. Instead, a doctor will ask questions about present symptoms; if they have a certain pattern over time, the doctor may diagnose IBS. A doctor may also perform tests to make sure symptoms are not from another condition.


There is no test for IBS. Your doctor will diagnosis IBS if you have the typical symptoms and have been tested for other disorders that can cause similar symptoms.Your doctor will ask about your medical history, dietary habits, and symptoms. Your doctor will examine you, testing your abdomen for tenderness and feeling to determine whether internal organs are larger than normal. The doctor will check for fever or weight loss. If you have any of these signs, you may have something other than IBS.

Depending on your medical history, your doctor may do tests to eliminate other diseases that may cause similar symptoms. These tests might include:

  • Blood tests

  • Stool sample, to check for blood or evidence of infection

  • Sigmoidoscopy, in which a flexible, lighted tube with a tiny camera on the end is inserted into the rectum and up the left side of the colon, or a colonoscopy, in which a longer tube examines the entire colon

  • Barium X-ray, in which a chalky solution is swallowed or pumped into the rectum to coat the inside of the gastrointestinal tract and highlight abnormalities

  • Asking you to stop eating or drinking certain foods for up to three weeks to determine if your diet is contributing to your symptoms (for example, your doctor may ask you to eliminate milk products if he or she suspects lactose intolerance)


One of the most helpful ways to treat IBS is to modify your diet. This can minimize symptoms, or it can reduce the likelihood that an IBS attack will occur.

In almost every case, different foods tend to trigger IBS symptoms. Doctors recommend monitoring what you eat so you can find out what you ate before an attack. After you discover your particular trigger foods, eliminate them from your diet. Some common IBS trigger foods include:

  • Cabbage, broccoli, kale, legumes and other gas-producing foods

  • Caffeine

  • Alcohol

  • Dairy products

  • Fatty foods, including whole milk, cream, cheese, butter, oils, meats and avocados

  • Raw fruits

  • Foods, gums and beverages that contain sorbitol, an artificial sweetener

The way you eat may help to create IBS symptoms. Eating large meals can cause cramping and diarrhea, so eating smaller meals more often may help some people with IBS. Eating quickly can cause you to swallow air, which can cause belching or gas.

Adding fiber to your diet, especially if constipation is one of your main symptoms, can help to loosen stools and reduce abdominal pain. At first, fiber will increase the amount of gas in your system, so add fiber gradually. Over time, the body adjusts to the effects of fiber and the gassiness will decrease. Fruits, vegetables and whole grain breads and cereals are good food sources of fiber. Your doctor may recommend a fiber supplement. Some experts believe that the fiber methylcellulose creates the least amount of gas, and brands of this fiber are often recommended for people with IBS. Psyllium is also a good source of fiber.

If your symptoms are not relieved after you eliminate trigger foods and add fiber, your doctor may prescribe medications. Depending on what your most difficult symptoms are, medications can include:

  • Antidiarrheals—loperamide (Imodium), diphenoxylate (Lomotil and other brand names), and euluxadoline (Viberzi). FDA guidelines advise that euluxadoine should only be taken by patients who still have their gallbladder.
  • Antispasmodics to reduce cramping—dicyclomine (Bentyl)
  • Pain-reducing agents—amitriptyline (Elavil), desipramine (Norpramin)
  • Constipation—osmotic laxatives, linaclotide (Linzess), and lubiprostone (Amitiza)

One other medication is available to treat severe diarrhea symptoms. Alosetron (Lotronex) is prescribed to treat women with IBS who have very severe diarrhea. If you take this medication, you have to receive it from a specialist with experience using the medication (the doctor must register with the drug manufacturer and receive training to be a prescriber) and you must sign a form stating that you are aware that life-threatening complications of a blocked, ruptured or damaged bowel may be caused by this medicine.


There is no cure for IBS, but symptoms can be managed by changing your diet, reducing stress and, if necessary, taking medication. It is common for IBS to be a chronic problem, although it resolves in some individuals.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2019 Apr 21
Definition & Facts for Irritable Bowel Syndrome. National Institutes of Health. National Institute of Diabetes and Digestive and Kidney Diseases.

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