Irritable Bowel Syndrome (IBS) is a disorder in which the bowels don't function as they should. They become very sensitive and then squeeze too hard or not hard enough, causing stools to move too quickly or too slowly through the intestines. IBS is also called "spastic colon" or "irritable colon."

IBS is one of the most common gastrointestinal disorders in the United States, affecting up to one in five Americans.

IBS is not a contagious illness or life-threatening disease, but it is a real medical disorder that can cause painful symptoms and compromise a person's quality of life.

There is no cure for IBS. It is a chronic condition, but symptoms can be managed through medication, diet, stress relief techniques, fiber therapy and other approaches.

Anyone can develop IBS at any age, but IBS symptoms typically begin around age 20. Women seem to develop it more often. Four of five people with IBS are women.

IBS is affected by genetic, physical, emotional and lifestyle factors, but the exact cause isn't known. It may result from changes in the muscle function or nervous system signals between the brain and bowel, including reactions to stress, hormones and other factors.

Different people have different IBS symptoms. A person can have one symptom or several, from mild to severe. The most common symptoms are bloating, constipation, diarrhea, gas, mucus in the stool and abdominal pain. Some people with IBS also report depression and anxiety.

IBS symptoms can be triggered by many different factors. Certain foods and drinks can be triggers, including fried, fatty or spicy foods and caffeinated or carbonated beverages. Hormonal changes from menstruation, stress and certain medications also can bring on symptoms. No two people have the same set of IBS triggers.

People with IBS tend to develop a "cluster" of symptoms, but typically one is more bothersome or severe than the rest. The type of IBS a person has is based on the predominant or main symptom they experience, such as constipation, diarrhea and "alternating" or "mixed" constipation and diarrhea.

Only a doctor can diagnose IBS. Sometimes, pinpointing IBS as the cause of a person's symptoms is a process of ruling out other disorders or diseases that could be responsible. The diagnosis process can include discussions with your doctor, physical exams, medical tests and referrals to other health care professionals.

If you think you have IBS, take the self-assessment quiz on this site. If your symptoms are not ones usually associated with IBS, such as fever and weight loss, you may have another condition or illness. In either case, make an appointment with your doctor.

There is no method for avoiding triggers or alleviating symptoms that works for everyone. There is no perfect IBS medication or treatment, either. But you can put together an individualized plan, with your doctor's help, for managing and treating your IBS symptoms. Your plan can encompass diet, fiber therapy, medications, exercise, stress management and/or "alternative medicine" approaches.

Diet has a major impact on the type, frequency and severity of your IBS symptoms. Changing what, how much and when you eat, especially with input from your doctor and a dietitian, can help to reduce symptoms. Adding more fiber, for example, is one way to control IBS through diet.

The physical movements of exercise help to stimulate normal contractions in your intestines, which can minimize IBS symptoms. Regular exercise also can help to decrease physical and emotional tension, build confidence and provide social opportunities, which can prevent people coping with IBS from feeling isolated by their condition.

In people with IBS, the intestines seem to be extra sensitive to emotional or physical stress. Their tendency to "overreact" can trigger or worsen the digestive problems of IBS. The better you're able to manage stress, the more successful you can be in reducing the frequency or severity of your IBS symptoms. Information on stress management techniques is available to people who join the Living Well with IBS program.

Some alternative and complementary therapies have been used and studied as IBS treatments, such as acupuncture, hypnotherapy, herbs and supplements and probiotics. Talk to your doctor to get input on alternative therapies.

The Digestion-Friendly Recipe Center on this site offers recipes developed specially for people with IBS by a dietitian and physician. To get access to the center, join the free Living Well with IBS program on this site.

No medicine can cure IBS, but there are a variety of over-the-counter and prescription medications that can ease particular IBS symptoms. Medication options include drugs that relax the bowel muscles, slow down or bulk up stool, change how the body senses pain, prevent bacteria from growing in the bowel or stimulate intestinal nerves.

If you have questions about a drug that's recommended to you, talk to your doctor and pharmacist first. You also can research prescription and over-the-counter medications online. This site contains links to certain drug information sites.

Read our tips for talking to your doctor and other health care professionals about your questions and concerns. The tips are available to you when you become a member of the Living Well with IBS program on this site.