Irritable Bowel Syndrome (IBS)

Irritable Bowel Syndrome (IBS)

Illustration of the anatomy of the digestive system, adult
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What is irritable bowel syndrome (IBS)?

Irritable bowel syndrome (IBS) is an intestinal disorder that causes the following:

IBS has inaccurately been called by many names, including the following:

IBS is called a functional disorder because there is no sign of disease when the colon is examined. Because doctors have been unable to find an organic cause, IBS often has been thought to be caused by emotional conflict or stress. While stress may worsen IBS symptoms, research suggests that other factors also are important.

IBS often causes a great deal of discomfort and distress, but it is not believed to:

It has not been shown to lead to serious, organic diseases, nor has a link been established between IBS and inflammatory bowel diseases such as Crohn's disease or ulcerative colitis.

What causes irritable bowel syndrome?

The digestion and propulsion of nutrients and fluids through the gastrointestinal system (GI) is a very complicated and very well-organized process. The GI tract has its own intrinsic muscles and nerves that connect, like an electrical circuit, to the spinal cord and brain. Neuromuscular events occurring in the GI tract are relayed to the brain through neural connections, and the response of the brain is also relayed back to the gastrointestinal tract. As a result of this activity, motility and sensation in the bowel are generated. An abnormality in this process results in a disordered propulsion of the intestinal contents, which generates the sensation of pain.

The exact cause of IBS is unknown. One theory is a person with IBS may have a colon that is more sensitive and reactive than usual, so it responds strongly to stimuli that would not affect others. The colon muscle of a person with IBS then begins to spasm after only mild stimulation or ordinary events such as the following:

Women with IBS seem to have more symptoms during their menstrual periods, suggesting that reproductive hormones can increase IBS symptoms.

What are triggers for IBS?

The most likely triggers for IBS are diet and emotional stress. Scientists have some clues as to why this happens. Consider the following:

What are the symptoms of IBS?

The following are the most common symptoms of IBS. However, each individual may experience symptoms differently. Symptoms may include:

Bleeding, fever, weight loss, and persistent, severe pain are not symptoms of IBS, but indicate other problems. The symptoms of IBS may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.

How is irritable bowel syndrome diagnosed?

Your doctor will obtain a thorough medical history, perform a physical examination, and obtain screening laboratories to assess for infection and inflammation. More than likely, all the screening tests and physical examination will be normal. In most cases IBS  is a diagnosis of exclusion. The laboratory tests, imaging studies, and procedures to be performed will be dictated by the history and physical examination. Tests and procedures that your doctor may order may include the following:

What is the treatment for IBS?

Specific treatment for IBS will be determined by your doctor based on:

Treatment may include:

What are good fiber sources?

FoodsModerate fiberHigh fiber
Bread Whole wheat bread, granola bread, wheat bran muffins, Nutri-Grain waffles, popcorn  
Cereal Bran Flakes, Raisin Bran, Shredded Wheat, Frosted Mini Wheats, oatmeal, Mueslix, granola, oat bran All-Bran, Bran Buds, Corn Bran, Fiber One, 100% Bran
Vegetables Beets, broccoli, brussels sprouts, cabbage, carrots, corn, green beans, green peas, acorn and butternut squash, spinach, potato with skin, avocado  
Fruits Apples with peel, dates, papayas, mangos, nectarines, oranges, pears, kiwis, strawberries, applesauce, raspberries, blackberries, raisins Cooked prunes, dried figs
Meat substitutes Peanut butter, nuts Baked beans, black-eyed peas, garbanzo beans, lima beans, pinto beans, kidney beans, chili with beans, trail mix

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Online Resources of Digestive Disorders


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