Irritable Bowel Syndrome

views updated

Irritable bowel syndrome


Irritable bowel syndrome (IBS) is a long-term or recurrent disorder of the gastrointestinal tract.


IBS is not a disease or even a malformation within the gastrointestinal tract. It is an array of symptoms (and is therefore classified as a syndrome) that arise because the intestines do not function properly. IBS is not readily understood and often is diagnosed by eliminating all other gastrointestinal diseases and disorders.

IBS presents with a dramatic change in bowel movements (constipation , diarrhea , or both), abdominal cramps, gas, bloating, and sometimes nausea. Symptoms can occur without warning, change over time,

or become intensified or lessen. Many patients with IBS report severe impact on their quality of life, often missing work or social events. IBS accounts for asmuch time off work or school as the flu and the common cold . The Veterans Administration has classified IBS, along with other multi-symptom chronic disorders such as fibromayalgia and chronic fatigue syndrome, as a disability for GulfWar Veterans.

In the past, IBS was known as colitis, spastic colon, nervous colon, or spastic bowel, implying that there was a psychological component to the syndrome. Since more women were found with the condition, it often became a catch-all diagnosis for intestinal symptoms of unknown origin that probably were due to emotional causes. That foundation encouraged psychological treatment and prescriptions for anti-depressants and sedatives. Over 40% of patients with IBS also have anxiety or depression ; it is unclear whether that is a result of the syndrome or a contributing factor to it. IBS is not a psychological or hysterical disorder. The symptoms are real, and patients with IBS need help managing their lives.

Diagnosing and managing IBS can be frustrating for patients and healthcare providers. Physicians are often frustrated by their inability to understand this disease and others like it, such as fibromyalgia , because it does not fit the current linear-reductionist paradigm, which is evidence-based and found through test results.

Though IBS is unpleasant, it does not lead to other more serious diseases or disorders of the bowel.


IBS is a functional disorder affecting 15–20% of Americans, with twice as many women as men reporting symptoms. The average patient waits more than three years before seeking medical help. In addition, many patients see three different healthcare professionals before a diagnosis is made.

IBS may be highly under-reported because of embarrassment associated with the condition. The International Foundation for Functional Gastrointestinal Disorders (IFFGD) speculates that as many as 70% of people with IBS have mild symptoms and do not see a doctor and only about 25% actually report IBS symptoms to their health care provider.

About two-thirds of patients diagnosed with IBS are women and 35–40% are men. Up to 40% of all visits to gastroenterologists are due to IBS symptoms. Many patients with IBS experience their first bout with IBS before age 35, but symptoms can first appear at age 50 or older. An early study in 2008 found a correlation between people with allergies (eczema, asthma , hay fever, etc.) and incidence of IBS.

Causes and symptoms


There is no known cause for IBS. Factors that may trigger an episode are known, but these vary as much among patients as the manifestation of symptoms. The American Society of Colon and Rectal Surgeons (ASCRS) suggests that faulty communication between the nervous system and the muscles of the bowel causes food to pass too quickly through the intestines or too slowly. Why this occurs is not yet understood.

Hormonal changes have been considered as a cause for IBS since women tend to have more episodes during their menstrual periods. However, many men also have the disorder, making female hormones an unlikely cause. Hormones may be stress factors that can trigger an episode.


Although there is no consistency of symptoms among patients with IBS, the most significant symptom is a marked change in bowel habits. A patient may report more frequent bowel movements or diarrhea. The stools themselves may become soft or watery and may be accompanied by mucous or oil. Other patients may have constipation. Gassiness, painful cramping, bloating, or nausea may also be present. Sometimes, there is the feeling that the bowel is not completely empty right after a bowel movement.

Often doctors classified IBS as either IBS-D for those with diarrhea or IBS-C for those with constipation. These classifications limit the scope of the syndrome because a number of patients have alternating diarrhea and constipation, and some patients start out with one set of symptoms, presenting consistently with diarrhea for example, and then switch to the other spectrum, consistently having constipation. IFFGD has tried to educate patients and physicians that IBS is a problem with the normal function of the bowel, not something that causes diarrhea or constipation. IFFGD reports that half of IBS patients have alternating bowel symptoms, with 30% of patients presenting only with diarrhea and 20% with constipation.

Patients with mild IBS may occasionally have an episode but the condition does not disrupt their normal activities. Patients with moderate to severe IBS have more frequent episodes, with some severe cases reporting difficulties daily. These patients find the physical pain and fatigue, coupled with constant trips to the bathroom and social isolation to be debilitating. Moreover, patients with IBS can never be certain when an episode will occur. They can be symptom-free for months or even years and then symptoms return.

As more patients report IBS, doctors are finding that some foods can trigger episodes. Eating specific foods such as gas-producing vegetables (onions, cabbage, broccoli, etc.), caffeine , chocolate, milk, carbonated drinks, fatty foods, and alcohol has been known to spawn an episode. Chewing gum or eating foods made with the artificial sweetener sorbitol can also trigger symptoms.

People who have an intolerance for lactose (found in milk and dairy products) or fructose (found in fruit or sweeteners) can also have bloating and diarrhea. This is food intolerance, not IBS. Some people with these same food intolerances may also have IBS.

Stress has been well documented to stimulate the stomach and the intestines. Even so, it is not a cause of IBS, but it can aggravate symptoms. Stress can be physical, psychological, environmental, or even dietary. An illness can be a physical stressor. Tension at work or the loss of a loved one can be psychological stressors. Travel or changes in climate are examples of environmental stressors. Eating a large meal or specific foods can be dietary stressors.


In order to diagnose IBS, a physician takes a detailed medical history and performs a physical exam. The Rome II criteria are commonly used to determine the extent of intestinal symptoms. The patient must have experienced symptoms for 12 weeks in a calendar year. These symptoms do not need to be on consecutive days or even weeks or months. The list of symptoms include pain that is relieved by a bowel movement, a change in the frequency of emptying the bowel, a change in the consistency of stools, feeling bloated, passing mucus, and feeling that the bowels are not empty after having a bowel movement.

For patients under 50, the Rome II criteria may be enough to warrant a diagnosis of IBS and begin treatment. Sometimes a doctor orders a stool sample to rule out intestinal bleeding. If the symptoms are severe; the patient has other gastrointestinal disorders, such as an ulcer or gastritis; or the patient is age 50 or over and just presenting with IBS symptoms; the doctor may order additional tests to rule out more serious diseases, such as Crohn's disease, ulcerative colitis, diverticulis, or colon cancer . Blood work is usually done to check for Celiac disease . The doctor may order a sigmoidoscopy or a colonoscopy ; an examination of the colon using a flexible tube with a camera on the end that is inserted through the anus. X rays of the lower intestinal tract or a computerized axial tomography (CAT) scan of the abdomen may also be ordered.


Since symptoms are variable and highly individual, education about the nature of IBS is an important part of treatment. The patient and the doctor need to know that although the syndrome is not life-threatening, it is at the least inconvenient, but often painful and debilitating. Some medications are available to help relieve the symptoms of IBS, but treatment usually involves managing the syndrome, not necessarily with medications. Lifestyle changes are critical to living with this syndrome.

For moderate symptoms, the patient should keep a diary to try to identify triggers that bring on symptoms. Changes in diet , eating style, and the frequency of meals can help. Regular exercise can stimulate intestinal muscles, which is especially helpful for those who have constipation. Medications can help manage some diarrhea or constipation. Stress management techniques such as meditation, progressive relaxation , and yoga may also provide relief.

Laxatives are often prescribed for patients with constipation, but some laxatives contain sorbitol, which is a known IBS trigger. Care should be taken when using laxatives to prevent laxative dependence. Common anti-diarrhea medications may be prescribed, such as loperamide (Immodium) and cholestyramine (Questran). Care should also be taken when using these medications because they can cause episodes of constipation. For patients who do not know how long a diarrhea episode will last (a few hours or a couple of days) they may prefer to wait out the episode rather than risk constipation.

For severe symptoms, the physician may offer more specific drug therapy for pain or to manage symptoms. They may also refer the patient to a pain treatment center or a therapist for help coping with the syndrome. In the past, some doctors have prescribed antidepressants, but these drugs have been found to have little impact for patients with IBS.

Alternative treatment

A number of alternative approaches have been used to treat IBS. These approaches offer a range of treatment to cover the degree of individuality within this syndrome. Alternative treatments include hypnosis (to reduce stress and manage pain), biofeedback , reflexology, homeopathy, acupuncture (for pain), and naturopathic medicine.

Herbal remedies have also been used, including Chinese traditional herbal medicine. Ginger, buckthorn, and peppermint have been tried. Since some patients' stomachs may be sensitive to peppermint, coated tablets protect the stomach but are released in the intestines. Chamomile, valerian, rosemary, and lemon balm are known to help with intestinal spasms.

A new treatment for digestive disorders was introduced in 2007. It uses live bacteria, called probiotics , taken in pill or powder form, or even in specially formulated yogurt (Activia). Bifidobacterium infantis has been tested in a number of small studies and found to have a positive effect on symptom relief, especially abdominal pain, bloating, and gas. This particular strain of bacteria is the microflora present in a baby's colon shortly after birth. It is considered beneficial bacteria within the intestine that can foster intestinal health.

Nutrition/Dietetic concerns

IFFGD recognizes that fiber can help or hinder IBS patients. Adding fiber has been more effective with patients with constipation than with those who have diarrhea. Care should be taken to add fiber to the diet in small amounts and not to add gas-producing foods if they are specific triggers. The American College of Gastroenterology has not endorsed the addition of fiber because they did not find it helpful to IBS patients.


  • Which tests will be used to diagnose IBS?
  • What type of treatment is best for my symptoms?
  • Could IBS be caused by other medications I am taking?
  • What type of dietary or lifestyle changes do you recommend?

For many IBS patients, leaving the intestinal tract empty for long periods and then eating something can produce an episode. Therefore, patients with IBS should eat at regular intervals to keep the digestive system active and working properly. In addition, eating a large meal can strain the intestinal tract and produce symptoms. Patients are often told to eat four or five small meals a day. They should eat slowly and in an environment that is relaxing, not rushed.


In 2008, the American College of Gastroenterology endorsed dietary and lifestyle modifications, patient education , and behavioral therapies for patients with IBS. The behavioral therapies they suggested were relaxation therapy, hypnosis, and counseling.


IBS can be a life-long condition, however, each year 10% of patients with IBS report symptom relief. IBS requires a commitment to life-long management of the syndrome.

A reliable test for IBS may soon be available. In 2008, a group of researchers found genetic biomarkers that may help identify IBS in patients.


It is impossible to prevent IBS, but patients with the syndrome can manage the condition and reduce the number of episodes or the severity of symptoms.

Many patients have found it helpful find support groups either locally or on the internet.


Anus —The opening into the lower end of the rectum.

Chronic fatigue syndrome —A poorly understood disorder that produces marked fatigue, poor immune response, digestive disturbances, and a range of other symptoms.

Colonoscopy —A test that examines the entire colon by inserting a camera on the end of a flexible tube through the anus into the colon.

Computerized axial tomography (CAT) scan —An imaging test used to take pictures of the body using a computer.

Crohn's disease —An irritable bowel disease marked by sporadic inflammation along the colon.

Fibromayalgia —A cluster of symptoms, including muscle pain, fatigue, and digestive disturbances, that seriously impact quality of life.

Fructose —A sugar found in fruit that is also used as a natural sweetener.

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

Lactose —A sugar found in dairy products.

Probiotics —Live bacteria that are reported to restore health to the intestines.

Sigmoidoscopy —A test that examines the lower portion of the colon by inserting a camera on the end of a flexible tube through the anus.

Sorbitol —An artificial sweetener known to trigger IBS symptoms in some patients.

Caregiver concerns

Living with IBS can be emotionally challenging, especially when others do not understand that managing this condition is more than just taking medication once or twice a day. It may be difficult for patients to communicate this condition to their friends or employers who might not understand that one day the patient may be fine and the next day the patient is not.

Managing IBS may require the patient to allow extra time when traveling for bathroom stops and rest breaks. Many patients routinely find out where the bathroom is when they enter a new space before they do anything else.

If there is a sudden marked change in bowel habits or if the patient is age 50 or over and experiences IBS symptoms for the first time, an appointment should be made to see a healthcare provider. If there is fever, weight loss , or recurrent vomiting, this could be a sign of a serious problem and warrants addition testing.



Aerssens, Jeroen, et al. “Alterations in Mucosal Immunity Identified in the Colon of Patients with Irritable Bowel Syndrome.” Clinical Gastroenterology and Hepatology. February 2008: 194–206.

Friedman, Lawrence S. “Irritable Bowel Syndrome.” Sensitive Gut 2005: 31.

Kajander, K., et al. “Clinical Trial: Multispecies Probiotic Supplementation Alleviates the Symptoms of Irritable Bowel Syndrome and Stabilizes Intestinal Microbiota.” Alimentary Pharmacology & Therapeutics January 2008: 48–57.

Lynch, April, John B. Webb, and Richard Sams II. “What are the Most Effective Nonpharmacologic Therapies for Irritable Bowel Syndrome?” Journal of Family Practice January 2008: 57–59.

Tobin, Mary C. “Atopic Irritable Bowel Syndrome: A Novel Subgroup of Irritable Bowel Syndrome with Allergic Manifestations.” Annals of Allergy, Asthma and Immunology January 2008: 49–53.

Trenev, Natasha. “IBS Sufferers Rejoice!” Total Health November 2007: 50–51.


“Irritable Bowel Syndrome.” Digestive System. July 30, 2007 [cited April 12, 2007].

“Treatment Options for IBS.” January 18, 2008 [cited April 12, 2008]. International Foundation for Functional Gastrointestinal Disorders.


American College of Gastroenterology (ACG), 4900 B South, 31 St., Arlington, VA, 22206, (703) 820-7400, (703) 931-4520,

American Gastroenterological Association (AGA), 7910 Woodmont Ave, 7th Floor, Bethesda, MD, 20814, (310) 654-2055,

American Society of Colon and Rectal Surgeons (ASCRS), 85 W. Algonquin Road, Suite 550, Arlington Heights, IL, 60005, (847) 290-9184, (847) 290-9203, [email protected],

International Foundation for Functional Gastrointestinal Disorders (IFFGD), P.O. Box 170864, Milwaukee, WI, 53217-8076, (414) 964-1799, (888) 964-2001, (414) 964-7176, [email protected],

Irritable Bowel Syndrome (IBS) Self-Help Group, 1440 Whalley Avenue, #145, New Haven, CT, 06515,

National Digestive Diseases Information Clearinghouse (NDDIC), 2 Information Way, Bethesda, MD, 20892-3570, (800) 891-5389, (301) 654-3810,

Janie F. Franz