Irritable bowel syndrome, or IBS, is a common condition that affects between 25 and 55 million Americans, the majority of whom are women. The condition most often occurs in people in their late teens to early 40s.
In essence, the condition is a combination of abdominal discomfort or pain and altered bowel habits: either altered frequency (diarrhea or constipation) or altered stool form (thin, hard, or soft and liquid).
IBS is not a life-threatening condition and it does not make a person more likely to develop other colon conditions, such as ulcerative colitis, Crohn's disease, or colon cancer, or any diseases of the heart or nerves. Yet IBS can be a chronic problem that can significantly impair quality of life in those that have it. For example, people with IBS miss work three times more than people without IBS and the condition is associated with absenteeism from school, decreased participation in activities of daily living, alterations of one's work setting (shifting to working at home, changing hours), or giving up work altogether.
What Are the Symptoms of IBS?
Among the symptoms associated with IBS are:
- Diarrhea (often described as violent episodes of diarrhea).
- Constipation alternating with diarrhea.
- Abdominal pains or cramps, usually in the lower half of the abdomen that are aggravated by meals and relieved by having a bowel movement. Often the person has more frequent bowel movements when they have pain and the stools are looser.
- Excess gas or bloating.
- Harder or looser stools than normal (rabbit like pellets or flat ribbon stools).
- Visible abdominal distension.
Some people with IBS have other symptoms not related to their digestive tract, such as urinary symptoms or sexual problems.
Symptoms of IBS tend to worsen with stress.
People with IBS have traditionally been described as having "constipation-predominant," "diarrhea-predominant," or an alternating pattern of constipation and diarrhea. Each type represents about a third of the overall IBS population.
What Causes IBS?
Two hundred years after the condition was first described, experts still don't completely understand what causes IBS symptoms.
Many experts think that it is a problem of bowel motility -- the muscles in the bowels don't contract normally -- affecting the movement of stool. But some studies don't show that the poor bowel motility correlates with symptoms. Also, drugs that alter motility don't seem to benefit most people with IBS.
Newer studies suggest that in IBS, the colon is hypersensitive, overreacting to mild stimulation by going into spasms. Instead of slow, rhythmic muscle contractions, the bowel muscles spasm. That can either cause diarrhea or constipation.
Another theory suggests that a number of substances that regulate the transmission of nerve signals between the brain and GI tract may be involved. These include serotonin, gastrin, motilin, and others.
Some have also suggested that there is a hormonal component to the condition, as it occurs in women much more frequently than in men. So far, studies have not borne this out.
A number of factors can "trigger" IBS, including certain foods, medicines, the presence of gas or stool, and emotional stress.
How Is IBS Diagnosed?
The diagnosis of IBS relies on the recognition of the symptoms as well as an extensive evaluation to rule out other causes. There are no specific lab tests that can be done to diagnose IBS. Therefore, your health care provider may run some tests to rule out other conditions such as:
- Food allergies or intolerances, such as lactose intolerance and poor dietary habits.
- Medications such as high blood pressure drugs, iron, and certain antacids.
- Enzyme deficiencies where the pancreas isn't secreting enough enzymes to properly digest or break down food.
- Inflammatory bowel diseases like ulcerative colitis or Crohn's disease.
The clinical diagnosis of IBS can be made by your doctor after a thorough history and exam and once other metabolic or structural conditions have been eliminated as a cause. Your health care provider may perform one or more of the following tests for further evaluation:
- Flexible sigmoidoscopy or colonoscopy to look for signs of intestinal obstruction or inflammation.
- Upper endoscopy if heartburn or indigestion is present.
- Blood testing to look for anemia (deficiency in red blood cells), thyroid problems, and signs of infection.
- Stool testing for blood or infections.
- Testing for lactose intolerance or gluten allergy (celiac disease).
- Specific testing to look for bowel motility problems.
How Is IBS Treated?
Treatment of IBS involves a collaborative effort between the doctor and the patient to manage symptoms and may consist of lifestyle changes and drug treatments.
Nearly all people with IBS can be helped, but no one treatment works for everyone. Usually, with a few basic changes in diet and activities, IBS will improve over time.
Nearly all people with IBS can be helped, but no one treatment works for everyone. Usually, with a few basic changes in diet and activities, IBS will improve over time. Here are some steps you can take to help reduce symptoms of IBS:
- Avoid caffeine (found in coffee, teas, and sodas).
- Increase fiber in your diet (found in fruits, vegetables, grains, and nuts).
- Drink at least three to four glasses of water per day.
- Don't smoke.
- Learn to relax, either by getting more exercise or by reducing stress in your life.
Try limiting the amount of milk and cheese you consume. Eat smaller meals more often or eat smaller portions. However, if you have IBS and are concerned about your calcium intake, you can try other sources of calcium. These sources include broccoli, spinach, turnip greens, tofu, yogurt, sardines, and salmon with bones, calcium-fortified orange juice and breads, calcium supplements, and some antacid tablets.
Keep a record of the foods you eat so you can figure out which foods bring on bouts of IBS. Common food "triggers" of IBS are red peppers, green onions, red wine, wheat, and cow's milk.