Irritable bowel syndrome

Irritable bowel syndrome (IBS) is a chronic disorder that involves the large intestine (colon). It's sometimes confused with another condition known as ulcerative colitis, a disorder that causes actual inflammation of the large intestine.


Causes/associated factors
Irritable bowel syndrome is thought to be caused by a motility disruption in the colon (the contraction of intestinal muscles and movement of the contents of the colon toward the rectum). Motility is regulated by nerves, electrical activity and hormones. What disrupts colon motility is unknown.
People who have IBS have sensitive colon muscles that respond strongly to even mild stimulation. If the muscle movement is too fast, the person may have diarrhea. If it's too slow, the person may be constipated. IBS can be aggravated by menstruation, certain foods or medicines, and stress. Some studies have shown a relationship between IBS symptoms and a history of verbal or sexual abuse.

About 15 to 20 percent of adults in the United States experience irritable bowel syndrome. The condition is more common in women. Although IBS doesn't damage the colon or increase the risk of developing cancer or other bowel diseases, the symptoms may cause discomfort and distress.


Signs/symptoms
Symptoms usually appear during late adolescence or early adulthood. They tend to come and go and may vary for each person. Common symptoms include:
abdominal pain that doesn't interfere with sleep, may worsen with eating or stress, and be relieved by having a bowel movement
feeling that you didn't completely empty your bowel after defecation
abdominal distention (stretched out or inflated abdomen)
increased frequency or urgency of bowel movements and looser stools with the onset of pain
constipation
diarrhea (may be frequent, explosive and urgent)
alternating constipation and diarrhea
mucus in the stools or stools shaped like small balls or ribbons
abdominal bloating, gas or cramping
heartburn or indigestion
nausea

Diagnosis
The doctor will review your medical history and do a physical exam. Diagnosis is based primarily on your symptoms. There is no specific test to diagnose irritable bowel syndrome, and the condition can't be detected through a colon exam. According to the Rome II Criteria, which was established by specialists to help doctors diagnose and minimize unnecessary testing, to be diagnosed with IBS you must have the abdominal discomfort and altered bowel habits for at least three months (not necessarily consecutively) and two of the following three symptoms:
pain relief with a bowel movement
symptoms associated with a change in frequency of bowel movement
symptoms associated with a change in the appearance of the stool
To rule out more serious conditions that may mimic IBS, you may need one or more of the following diagnostic tests:

blood tests
stool tests (such as cultures or tests for blood or parasites)
barium enema (an X-ray of the bowel after the doctor inserts barium, a contrast dye, into the rectum)
upper gastrointestinal endoscopy (using an endoscope -- a thin, flexible tube equipped with a camera lens and light -- to see the inside of the small intestine)
sigmoidoscopy (examination of the rectum and lower part of the colon)
colonoscopy (examination of the entire colon)
abdominal ultrasound (using sound waves to create an image of your abdomen)
lactose intolerance testing

Treatment
Treatment depends on the severity of your symptoms. Your doctor may recommend the following self-care steps:
Eat a well-balanced diet. Don't skip meals or overeat.

Drink plenty of fluids. Hot drinks may be soothing.

Increase your fiber intake. Do it slowly to give your system time to adjust. (You may need to exclude dietary fiber when you have acute diarrhea, however.)

Reduce or eliminate caffeine and alcohol intake, especially when you have diarrhea and cramps.

Keep excess air out of your system by avoiding chewing gum, carbonated beverages and hard candy.

Keep a diary, including records of what you eat. Patterns may emerge to help explain what triggers your symptoms.

Avoid foods that trigger symptoms, such as chocolate and fried, fatty or greasy foods. Also avoid foods that may produce gas, such as brussels sprouts, onions, cabbage, raisins, broccoli and cauliflower. Foods containing sorbitol, an artificial sweetener, and fructose, a sugar found in some fruits, can also be culprits.

Use lactase or lactase-treated dairy products if milk or other dairy products intensify your symptoms.

Recognize where stress exists in your life and take steps to reduce it. You may want to consider professional counseling to learn stress management and relaxation techniques.

Exercise regularly. Try taking a daily walk.

Place a heating pad on your abdomen or take a warm bath. (Caution: If you have undiagnosed abdominal pain, check with your doctor before using heat.)

Learn about biofeedback. You may be able to control your pain by changing the way you focus your attention.
Your doctor may also prescribe the following medications:

an antispasmodic medication to prevent or relieve muscle contractions
an antidepressant, which may be helpful even when you're not depressed
a sedative or tranquilizer
an antidiarrheal medication, laxatives or fiber supplements
Two newer medications are available by prescription to treat IBS in women. Tegaserod maleate (Zelnorm) is used to help improve pain, bloating and constipation when constipation is the predominant symptom of IBS. Alosetron hydrocholride (Lotronex) may be prescribed for women who have severe diarrhea as the predominant symptom and have not responded to conventional therapies. Doctors will be asked to enroll patients in a special program intended to minimize any risk with this medication.


Complications
Irritable bowel syndrome has not been proven to cause any serious diseases. Because symptoms of IBS may mimic symptoms of a more serious condition, however, ignoring them could be dangerous. See your doctor if you experience any change in bowel habits or your symptoms disrupt your normal activities, especially if the symptoms appear suddenly. Symptoms that may indicate a more serious problem include fever, bleeding, weight loss or persistent, severe pain.

Pregnancy-specific information
The symptoms of IBS may be altered in pregnancy, but the condition itself is not considered detrimental to mother or baby.

Senior-specific information
Older adults who have IBS often have a chronic history of bowel problems. The number of elderly adults who have IBS is unknown, but it's considered uncommon to develop new symptoms of this condition during the senior years.