Article updated and reviewed by Christian D. Stone, M.D., Assistant Professor of Medicine, Division of Gastroenterology, Washington University in St. Louis School of Medicine on May 19, 2005.
IBS is known by various other names such as irritable colon, spastic colon, spastic bowel, and functional bowel disease. It is not accurate to use the term colitis when describing IBS. Colitis means there is inflammation in the colon but this is not the case in IBS.
The colon (large intestine) is responsible for packaging and eliminating stool. As food moves through the colon it absorbs water while forming stool. Muscle contractions (squeezing motions) in the colon push the stool toward the rectum (the lower five inches of the large intestine). These contractions are controlled by nerves, hormones and by electrical activity in the colon musculature and result in defecation or bowel movement.
Normal bowel function varies widely from person to person, but doctors generally agree that normal bowel function ranges from three stools a day to three each week. A normal movement is one that is formed but not hard, contains no blood, and is passed without cramps or pain. However, when colonic nerves become "irritated" the muscle contractions may become too hard (causing abdominal pain), may stop (causing constipation and bloating), or may accelerate (causing diarrhea and an urgency to have a bowel movement). Irritated colonic nerves also make the colon very sensitive to distention which may also cause pain. Emotional factors such as stress, anxiety or depression are not necessary to cause disease but still may play a role in IBS by worsening symptoms and interfering with the ability to cope with symptoms.
Though IBS can cause a great deal of discomfort, it can almost always be managed and does not lead to any other serious diseases. With attention to proper diet, stress management, and sometimes prescription medications, most people with IBS can keep their symptoms under control.
The symptoms of IBS are:
- abdominal pain with gassiness, crampy pain, or bloating
- alternating constipation and diarrhea
- feeling the need for a bowel movement after just having one
- feeling a strong urge to have a bowel movement, especially after eating
In some patients, the symptoms of IBS can be aggravated by factors such as emotional conflict, stress, food, alcohol, caffeine, change in daily routine or a woman's menstrual period.
IBS is diagnosed based on clinical criteria only. There is no routine test or examination that can help make the diagnosis. A detailed medical history, with emphasis on symptoms and symptom frequency, is the most important and the only necessary part of an evaluation for IBS. Physical examination, laboratory tests such as a CBC (complete blood count), x-rays, or diagnostic procedures such as colonoscopy (examination of the rectum and sigmoid colon through a viewing instrument inserted into the rectum) are not needed to make a diagnosis of IBS but may be performed to ensure that other diseases are not present.
The severity of IBS will determine the method of treatment. In general, treatment is aimed first at relieving the gastrointestinal symptoms. In some cases, however, emotional or psychological factors are also targeted as part of the treatment plan. It is important to emphasize that no single regimen works for most people with IBS. Symptoms are quite variable and may change significantly over time, therefore therapy must be individualized. Moreover, for many, treatment must continue over the long-term, as IBS is a chronic condition.
Conservative treatment of mild IBS involves changing the person's diet and alleviating stress. For some, but not all patients, a high-fiber, low fat diet is recommended. Fat strongly stimulates contractions of the colon and fiber keeps the colon mildly distended, which may help prevent spasms. Foods such as whole grain breads and cereals, beans, fruits and vegetables are good sources of fiber. Some doctors may suggest using an over-the-counter fiber supplement. Use of fiber is most important for patients with predominantly constipation as their main complaint. Fiber may not be as useful for patients with predominantly bloating or diarrhea.
Avoiding alcohol and caffeine are also important in controlling diarrhea in IBS.
Recommended lifestyle changes consist of regular exercise, alleviating stress, getting a good night's sleep, reserving enough time to have a bowel movement and having a bowel movement when needed.
For moderate to severe IBS, the doctor may recommend a pharmaceutical approach to ease the symptoms of IBS. Cramping and pain may be relieved by an antispasmodic medicine such as hyoscyamine (Anaspaz, Cystospaz, Levsin) or dicyclomine (Bemote, Bentyl, Di-Spaz). For diarrhea, the doctor may recommend loperamide (Imodium) or cholestyramine (Questran) and for constipation, osmotic laxatives such as lactulose (Chronulac, Kristalose) or sorbitol are helpful. A newer medication approved only for constipation-predominant IBS is tegaserod (Zelnorm). Its action involves stimulating the colon to contract to promote regular bowel movements and reduce bloating.
For patients suffering from frequent and severe pain that impairs their daily functioning, a physician may prescribe an antidepressant such as amitriptyline or nortriptyline. These drugs work by increasing the release of neurotransmitters in the brain, thereby preventing the transmission of pain and reducing pain perception.
Although doctors note that IBS is a disorder of colon motility and sensation, psychological and behavioral treatments represent important supplemental therapy for patients with IBS, regardless of the severity of the condition. Simple forms of relaxation or exercise (e.g., baths, golf, tennis, and rest periods) may reduce tension and enable the patient to feel more in control. This is important, because many patients with IBS come to the physician already with a feeling of loss of control over their lives. Insight or cognitive psychotherapy, hypnotherapy, biofeedback or other structured relaxation techniques are examples of behavioral treatments that may be considered in selected patients.
Are there any signs or symptoms that may indicate another disorder?
Are you going to prescribe any medications?
What are the side effects of the medications?
Are biofeedback techniques or hypnotherapy successful in treating irritable bowel syndrome?
Can this increase the chances of developing colon cancer?
Editorial review provided by VeriMed Healthcare Network.