Irritable bowel syndrome (IBS) is not a disease; it is a disorder that interferes with the normal function of the large intestine (colon) and is characterized by cramping, abdominal pain, bloating, constipation, and diarrhea.
In the past, it has been called colitis, mucous colitis, spastic colon, or spastic bowel. IBS involves how the muscles in the intestines work and how pain is perceived in the bowel, but it does not permanently damage the colon, and does not lead to bleeding or a serious disease such as cancer or inflammatory bowel diseases (Crohn's disease or ulcerative colitis). Most people can control their symptoms with diet, stress management, and medications. But for some people, IBS can interfere with work, social events, or travel.
The ailment is twice as common among women as men, but this could partly be because women are more open about health problems. It usually begins around age 20. Many people let IBS persist for several years before seeing a health care provider.
The cause of IBS is not known. People with IBS may have a colon that is more sensitive and reactive than usual to certain foods or stress. Abnormally high levels of serotonin, a neurotransmitter found in the brain and in the gastrointestinal tract (GI), are found in people with IBS. This makes the pain receptors in the GI tract more sensitive. IBS tends to occur more often among people with depression and anxiety. Other possible causes include:
Stress (feeling mentally or emotionally tense)
Bacterial infections of the GI tract
Undiagnosed mild celiac disease (an autoimmune disease in which people cannot digest gluten, a substance found in wheat, rye, and barley)
Increased estrogen, which seems to influence the activity of the bowels; on average, women's symptoms worsen around menstruation
The symptoms that define IBS vary from person to person but include abdominal pain that is relieved by a bowel movement; diarrhea or constipation -- sometimes both; a sense of urgency to pass stool; incomplete passage of stool; mucus in the stool; and gas or bloating. For a diagnosis of IBS, the symptoms have to be present for at least 12 weeks out of the previous 12 months. The 12 weeks do not have to be consecutive.
The symptoms usually aren't continuous, but occur from a few times a week to once a month. IBS also might go away for years and suddenly return. What distinguishes it from other GI upsets is the frequency and severity of symptoms. Bleeding, fever, weight loss, and persistent severe pain are not symptoms of IBS. If you have these symptoms you should see your health care provider.
Anyone with the symptoms of IBS should tell his or her health care provider.
There is no cure for IBS, but symptoms can be relieved. Many prescription medications are used to treat IBS, including anti-depressants, anti-anxiety drugs, bowel stimulants, and anti-spasmodic drugs to prevent diarrhea (Lomotil or Imodium). Fiber supplements or occasional laxatives for constipation may help, but talk to your health care provider before trying these. Stress management techniques are an important part of treatment. Relaxation training, counseling, regular exercise, and adequate sleep can help reduce the response to stress that triggers colon spasms.
Dietary changes may help relieve symptoms. By keeping a list of the foods that seem to increase symptoms, you can learn what foods to avoid. Increasing fiber will help relieve constipation but will not help diarrhea or pain. Getting enough liquids, especially if you have diarrhea, is important. Carbonated beverages may cause increased gas, as can eating too quickly or chewing gum. Smaller meals or smaller portions may also help relieve symptoms.
Antidepressants can help those with psychological distress, and also can independently ease pain. People sometimes use herbal teas such as chamomile and ginger.
The FDA advises health care providers, patients, families, and caregivers of adults and children that they should closely monitor all patients beginning therapy with antidepressants and when doses are either increased or decreased, for worsening depression and suicidal thinking. The FDA also advises that these patients be observed for certain behaviors associated with these drugs, such as anxiety, agitation, panic attacks, insomnia, irritability, hostility, impulsivity, severe restlessness, hypomania, and mania. It is recommended that physicians be particularly vigilant in patients who may have bipolar disorder.