Irritable bowel syndrome


Irritable bowel syndrome (IBS) is a common gastrointestinal condition characterized by abdominal pain and cramps; changes in bowel movements ( diarrhea , constipation , or both); gassiness; bloating; nausea ; and other symptoms. There is no cure for IBS; however, dietary changes, stress management, and sometimes medications are often able to eliminate or substantially reduce its symptoms.


IBS is the name people use today for a condition that was once called—among other things—spastic colitis, mucous colitis, spastic colon, nervous colon, spastic bowel, and functional bowel disorder. Some of these names reflected the now outdated belief that IBS is a purely psychological disorder, a product of the patient's imagination. Although modern medicine recognizes that stress, anxiety and depression can trigger IBS attacks, medical specialists agree that IBS is a genuine physical disorder—or group of disorders—with specific identifiable characteristics. IBS is considered a functional disorder because it is thought to result from changes in the activity of the major part of the large intestine (the colon).


IBS is one of the most common functional gastrointestinal disorders, affecting 10-20 percent of adults in the United States. Research has demonstrated that symptoms compatible with IBS are about as common in school-age children as in adults. IBS normally makes its first appearance during young adulthood, and symptoms usually begin at about age 20. Women with IBS represent over 70 percent of IBS sufferers. IBS is responsible for more time lost from school and work than any medical problem—other than the common cold . It accounts for a substantial proportion of the patients seen by specialists in diseases of the digestive system (gastroenterologists).

A community-based study of 507 middle school and high school students by Hyams, et al, found that 6-14 percent of the adolescent population had IBS symptoms. Anxiety and depression scores were significantly higher for this group. Eight percent of all the students in the study had seen a physician for abdominal pain in the previous year.

Causes and symptoms


Although the exact cause or causes of IBS are unknown, research suggests that people with IBS may have a colon that is more sensitive and reactive to certain foods and stress.

After food is digested by the stomach and small intestine, the undigested material passes in liquid form into the colon, which absorbs water, nutrients and salts. Normally, the colon is quiet during most of that period except after meals, when its muscles contract in a series of wavelike movements called peristalsis. Peristalsis helps absorption by bringing the undigested material into contact with the colon wall. It also pushes undigested material that has been converted into solid or semisolid feces toward the rectum, where it remains until a bowel movement occurs.

In IBS, however, the normal rhythm and intensity of peristalsis is disrupted. Sometimes there is too little peristalsis, which can slow the passage of undigested material through the colon and cause constipation. Sometimes there is too much, which has the opposite effect and causes diarrhea. In other cases, peristalsis can be spasmodic, causing sudden strong muscle contractions that come and go.

DIET Some foods and beverages appear to play a key role in triggering IBS attacks. Certain foods and drinks may disrupt peristalsis in IBS patients, which may explain why IBS attacks often occur shortly after meals. Some of the chief culprits include:

  • chocolate
  • dairy products
  • caffeine (in coffee, tea, colas, and other drinks)
  • carbonated beverages (colas, pop, soda)
  • wheat
  • rye
  • barley
  • excess alcohol

Other foods also have been identified as problems, and the pattern of what can and cannot be tolerated is different for each person.

STRESS Stress—feeling mentally or emotionally tense, troubled, angry or overwhelmed—stimulates colon spasms in people with IBS since there is a close nervous system connection between the brain and the intestines. A large network of nerves control the normal rhythmic contractions of the colon. Although researchers do not yet understand all of the links between changes in the nervous system and IBS, they point out the similarities between mild digestive upsets and IBS. Just as healthy people can feel nauseated or have an upset stomach when under stress, people with IBS react the same way, but to a greater degree.

MENSTRUATION IBS symptoms sometimes intensify during menstruation , suggesting female reproductive hormones may trigger the condition.


The symptoms of IBS tend to rise and fall in intensity, rather than grow steadily worse over time. Symptoms always include:

  • abdominal pain, which may be relieved by defecation
  • diarrhea
  • constipation
  • diarrhea alternating with constipation

Other symptoms, which vary from person to person, include:

  • cramps
  • gassiness
  • bloating
  • nausea
  • passage of mucus during bowel movements
  • abnormal stool frequency—defined as greater than three bowel movements per day or less than three bowel movements per week
  • abnormal stool form (lumpy, hard, loose, or watery stool)
  • abnormal stool passage (straining, urgency, or feeling of incomplete bowel movement)

In general, symptoms are not present all the time and do not interfere with school and other normal activities. IBS symptoms rarely occur at night and disrupt the patient's sleep . Moderate IBS occasionally disrupts normal activities.

When to call the doctor

If a child has the following symptoms, the parent should contact the child's pediatrician or gastroenterologist:

  • abdominal pain or diarrhea that wakes the child during the night
  • persistent or severe abdominal pain
  • unexplained weight loss
  • rectal bleeding
  • fever
  • family history of irritable bowel disease


The Rome II criteria are the accepted diagnostic criteria for IBS. These criteria were developed by an international group of pediatric gastroenterologists and include:

  • Continuous or recurrent abdominal discomfort or pain for at least three months that is: a) Relieved with defecation and/or b) Associated with a change in frequency and/or c) Associated with a change in appearance of stool. Two or three of these features are present with an IBS diagnosis.
  • No structural or metabolic abnormalities are present that may be responsible for the IBS symptoms.

The diagnosis of IBS is further supported by the presence of the symptoms listed previously. In addition, the primary pediatrician or gastroenterologist may confirm the diagnosis of IBS after questioning the child (if old enough to provide an accurate history of symptoms) or parent about his or her physical and mental health (the medical history), performing a physical examination, and ordering laboratory tests to rule out other conditions that resemble IBS, such as Crohn's disease and ulcerative colitis.

Diagnostic tests may include stool or blood tests, hydrogen breath test, or an x ray of the bowel, called a barium enema. When symptoms continue even after treatment, endoscopic tests such as a colonoscopy or sigmoidoscopy may be performed. An endoscopic test is an internal examination of the colon using a flexible instrument (a sigmoidoscope or colonoscope) that is inserted through the anus.

A nutritional assessment performed by a registered dietitian may be included in the child's diagnostic evaluation. The nutritional assessment includes a review of the child's fiber intake as well as his or her usual consumption of sugars such as sorbitol and fructose—common culprits of diarrhea.


Dietary changes and sometimes medications are considered the keys to successful treatment. Psychosocial difficulties are also addressed and treated with therapy or counseling as needed. Treatment requires a long-term commitment; six months or more may be needed before the child notices substantial improvement.

Alternative treatment

Alternative and complementary therapies include approaches that are considered to be outside the mainstream of traditional health care. Alternative and traditional approaches to IBS treatment overlap to a certain extent. Like traditional doctors, alternative practitioners advise a high-fiber diet to reduce digestive system irritation. They also suggest avoiding caffeine and fatty, gassy, or spicy foods, as well as alcohol. Recommended stress management techniques include yoga , meditation, guided imagery, hypnosis, biofeedback, and reflexology. Reflexology is a foot massage technique that is thought to relieve diarrhea, constipation, and other IBS symptoms.

The list of alternative treatments for IBS is quite long. It includes aromatherapy, homeopathy, hydrotherapy, juice therapy, acupuncture, chiropractic, osteopathy, naturopathic medicine, and Chinese traditional herbal medicine.

Normal and diseased (center) colons. Areas of constriction in the colon cause constipation, while areas of distention cause diarrhea. ( 1995 John Bavosi/Science Photo Library. Custom Medical Stock Photo, Inc.)
Normal and diseased (center) colons. Areas of constriction in the colon cause constipation, while areas of distention cause diarrhea.
(© 1995 John Bavosi/Science Photo Library. Custom Medical Stock Photo, Inc.)

Before learning or practicing any particular technique, it is important for the parent/caregiver and child to learn about the therapy, its safety and effectiveness, potential side effects, and the expertise and qualifications of the practitioner. Although some practices are beneficial, others may be harmful to certain patients.

Relaxation techniques and dietary supplements should not be used as a substitute for medical therapies prescribed by a doctor. Parents should discuss these alternative treatments with the child's doctor to determine the techniques and remedies that may be beneficial for the child.

Nutritional concerns

Dietary changes, including a low-fat, high-fiber diet, may help decrease IBS symptoms. The addition of wheat bran or other fiber may be suggested to decrease symptoms. The formula for determining the recommended fiber intake for children, as advised by the American Dietetic Association, is to take the child's age plus five to equal the grams of dietary fiber the child should consume daily. Fiber should be added gradually to the child's diet.

The doctor may recommend a lactose-free diet for two or three weeks to determine if lactose intolerance is causing the symptoms. Lactose is the milk sugar found in dairy products. Lactose intolerance is a common condition in up to 40% of patients with IBS. During the lactose-free period, the child should avoid all products containing lactose. The parent and child are asked to record the intake of all foods and beverages and note when symptoms occur after eating or drinking.

To identify other problem-causing foods or beverages, it is helpful for the parent and child to keep a diary of symptoms for two or three weeks, including daily activities, meals, symptoms and emotions. The doctor can then review the diary with the parent and child to identify possible problem areas.

In addition to lactose, known problem-causing substances include caffeine, beans, onions, cabbage, cucumbers, broccoli, fatty foods, alcohol, and certain medications. Once the specific substances that trigger symptoms are identified, they should be avoided. A registered dietitian can help the parent and child make specific dietary changes.

If lactose intolerance is a problem, the child may need to take calcium supplements or choose other foods high in calcium to meet the recommended daily requirement. If lactose intolerance is not a problem, the child can still have milk or milk products.


Medications affect each child differently, and no one medication works for every child with IBS. The child and parent will need to work with the doctor to find the best combination of medicine, diet, counseling and support to manage symptoms.

Stool softeners such as polyethelene glycol (Miralax) or an over-the-counter laxative may be recommended for constipation. Mineral oil also may be helpful. However, it is important not to use over-the-counter remedies without first consulting with the child's doctor.

Tricyclic antidepressants in low doses may be prescribed for pain relief. Antidepressants work by blocking pain transmission from the nervous system. Antispasmodic medications can slow bowel contractions and decrease diarrhea. Anticholinergics may help control intestinal cramping. Keep in mind that the effectiveness of these drugs to treat IBS has not been studied extensively in children.


Anus —The opening at the end of the intestine through which solid waste (stool) passes as it leaves the body.

Barium enema —An x ray of the bowel using a liquid called barium to enhance the image of the bowel. This test is also called a lower GI (gastrointestinal) series.

Colonoscopy —An examination of the lining of the colon performed with a colonoscope.

Constipation —Difficult bowel movements caused by the infrequent production of hard stools.

Crohn's disease —A chronic, inflammatory disease, primarily involving the small and large intestine, but which can affect other parts of the digestive system as well.

Defecation —The act of having a bowel movement or the passage of feces through the anus.

Diarrhea —A loose, watery stool.

Endoscopy —Visual examination of an organ or body cavity using an endoscope, a thin, tubular instrument containing a camera and light source. Many endoscopes also allow the retrieval of a small sample (biopsy) of the area being examined, in order to more closely view the tissue under a microscope.

Feces —The solid waste, also called stool, that is left after food is digested. Feces form in the intestines and pass out of the body through the anus.

Gastroenterologist —A physician who specializes in diseases of the digestive system.

Hydrogen breath test —A test used to determine if a person is lactose intolerant or if abnormal bacteria are present in the colon.

Lactose —A sugar found in milk and milk products.

Peristalsis —Slow, rhythmic contractions of the muscles in a tubular organ, such as the intestines, that move the contents along.

Sigmoidoscopy —A procedure in which a thin, flexible, lighted instrument, called a sigmoidoscope, is used to visually examine the lower part of the large intestine. Colonoscopy examines the entire large intestine using the same techniques.

Ulcerative colitis —A form of inflammatory bowel disease characterized by inflammation of the mucous lining of the colon, ulcerated areas of tissue, and bloody diarrhea.

Counseling and support

Psychological counseling or behavioral therapy may be recommended for some patients to reduce anxiety and stress and to learn to cope with the symptoms of IBS. Biofeedback, guided imagery, relaxation therapy, hypnosis, and cognitive-behavioral therapy are examples of behavioral therapy. An ongoing and supportive doctor-patient relationship is also very important. The child and family must be reassured that although IBS causes symptoms that are uncomfortable and sometimes painful, it is not a harmful condition and does indicate a serious problem.


IBS is not a life-threatening condition. It is not an anatomical or structural defect, nor an identifiable physical or chemical disorder. IBS does not cause intestinal bleeding or inflammation, nor does it cause other gastrointestinal diseases or cancer . Although IBS can last a lifetime, in up to 30% of cases the symptoms eventually disappear. Even if the symptoms cannot be eliminated, with appropriate treatment they usually can be managed enough so IBS becomes merely an occasional inconvenience.


Nutritional concerns

To help prevent or decrease the child's symptoms, parents can:

  • help the child identify and avoid problematic foods
  • work with a registered dietitian to facilitate specific dietary changes
  • incorporate changes in the child's diet gradually so his or her body has time to adjust
  • establish set times for meals; not allowing the child to skip a meal
  • encourage the child to drink at least eight 8-ounce glasses of water per day
  • serve small portions during meals
  • teach the child to eat slowly, to avoid swallowing too much air that can produce excess gas
  • try offering smaller, more frequent meals
  • keep a regular schedule for bathroom visits

Parental concerns

Parents should reinforce with the child that IBS is not a life-threatening condition and that dietary changes and stress reduction can help reduce symptoms. Remind the child that six months or more may be needed before he or she notices substantial improvement in symptoms.



Goldberg, Burton, John W. Anderson, and Larry Trivieri. Alternative Medicine: The Definitive Guide, 2nd Edition. Berkeley, CA: Ten Speed Press, 2002.

Lynn, Richard B., and Lawrence S. Friedman. "Irritable Bowel Syndrome." In Harrison's Principles of Internal Medicine, 16th Edition. Anthony S. Fauci, et al. New York: McGraw-Hill Professional, 2004.

Van Vorous, Heather. Eating for IBS Diet and Cookbook. New York, NY: Marlowe & Company, 2000.


Dalton, Christine B., and Douglas A. Drossman. "Diagnosis and Treatment of Irritable Bowel Syndrome." American Family Physician (Feb. 1997): 875+.

Hyams, J.S., et al. "Abdominal Pain and Irritable Syndrome in Adolescents: A Community-Based Study." Journal of Pediatrics (Aug. 1996): 220+.

Jarrett, Monica, et al. "Recurrent Abdominal Pain in Children: Forerunner to Adult Irritable Bowel Syndrome." Journal for Specialists in Pediatric Nursing (July-Sept. 2003): 81+.


American College of Gastroenterology (ACG). P.O. Box 3099, Alexandria, VA 22302. (703) 820-7400. Web site: .

American Gastroenterological Association. 4930 Del Ray Ave., Bethesda, MD 20814. (301) 654-2055. Web site: .

International Foundation for Functional Gastrointestinal Disorders (IFFGD). P.O. Box 170864, Milwaukee, WI 53217-8076. (888) 964-2001. E-mail: Web site: .

Irritable Bowel Syndrome (IBS) Association. 1440 Whalley Ave., #145, New Haven, CT 06515. E-mail: Web site: .

Irritable Bowel Syndrome Self Help and Support Group. 1440 Whalley Ave., #145 New Haven, CT 06515. E-mail: Web site: .

National Digestive Diseases Information Clearinghouse (NDDIC). 2 Information Way, Bethesda, MD 20892-3570. (800) 891-5389. E-mail: Web site: .


About IBS. Available online at

Howard Baker

Other articles you might like:

User Contributions:

Comment about this article, ask questions, or add new information about this topic: