Irritable Bowel Syndrome
Irritable bowel syndrome or IBS is a chronic disorder of the colon. The cause is as yet unknown. Doctors call it a functional disorder because there is no sign of the disease when the colon is examined by x-ray or colonoscopy. However, IBS causes a variety of symptoms including lower abdominal pain, gas, bloating, constipation, diarrhoea or alternating constipation and diarrhoea. Through the years, IBS has been called many names – mucous colitis, spastic colon, spastic bowel and functional bowel disease. Most of the terms are inaccurate. Colitis, for instance, means inflammation of the colon. IBS on the other hand, does not cause inflammation and should never be confused with the more serious disorder colitis.
Though IBS can cause a great deal of discomfort, it is not serious and does not lead to any serious disease. With attention to proper diet, sometimes stress management and sometimes medication, most people with IBS can keep their symptoms under control.
What are the symptoms?
It is important to remember that normal bowel function varies widely from person to person. 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. People with IBS usually have some combination of constipation and diarrhoea as well as pain, gas and abdominal bloating. Most people with IBS have episodes of lower abdominal pain and constipation, sometimes followed by diarrhoea. People in this group may have loose bowel movements after breakfast almost every day. These may be followed by episodes of diarrhoea after other meals, following stressful events or for no apparent reason. Although IBS is usually a mild annoyance, for some people it can be disabling. Patients in the latter group may be afraid to go to dinner parties, seek employment or travel on public transportation.
What causes IBS?
Because doctors have been unable to pinpoint its organic cause, IBS has often been considered to be caused by emotional conflict or stress. While stress may certainly be a factor, recent studies indicate that other factors may be involved. Most IBS symptoms are related to an abnormal motility (movement) pattern of the colon. The colon connects the small intestine with the anus (bottom). Approximately 5 feet long, the colon’s major function is absorbing water and salts from digestive contents that enter from the small intestine. Two litres of liquid matter enters the colon from the small intestine each day. This material remains there for one to two days until most of the fluid and salts are absorbed back into the body. The stool then passes through the colon by a delicate pattern of movements to the rectum where it is stored until a bowel movement occurs. Movements of the colon are controlled by nerves and hormones and by electrical activity in the colon muscle. The electrical activity serve as a ‘pacemaker’ similar to the mechanism that controls heart function. Movements of the colon propel the contents slowly back and forth, but mainly toward the rectum. Segments of the colon also contract periodically to promote the absorption of water from the faeces. In people who have IBS, the muscle of the lower portion of the colon contracts abnormally. An abnormal contraction or spasm may be related to episodes of crampy pain. Sometimes the spasm delays the passage of stool, leading to constipation. At other times, the spasm leads to more rapid passage of faeces and the result is diarrhoea.
How is IBS diagnosed?
IBS is a diagnosis that doctors reach after more serious organic diseases have been excluded. This process is necessary because IBS offers doctors no signposts to help identify the disorder. A complete medical history that includes a careful description of symptoms, a physical examination and specific laboratory tests will be done. Also, Dr White will most likely order some diagnostic tests such as a colonoscopy to eliminate organic causes of your symptoms. Unless your symptoms change, you usually do not need to undergo these tests again.
How does diet and stress affect IBS?
The potential for abnormal function of the colon is always present in people with IBS, but something must trigger it to cause symptoms. The factors that seem to be the most likely culprits are diet and emotional stress. Many people note that their symptoms occur following a meal or when they are under stress. Why this happens no one is sure, but scientists have some clues. Eating causes contractions of the colon. Normally this response may cause an urge to have a bowel movement within 30 to 60 minutes after a meal. In people with IBS, the exaggerated reflex can lead to cramps and sometimes diarrhoea.
The strength of the response is directly related to the number of calories in a meal and especially the amount of fat in a meal. Fat in any form is the strongest stimulus of colonic contractions after a meal. Fat is primarily found in meats, especially bacon and sausages, poultry skin, dairy products including milk, cream, cheese and butter, vegetable oils, margarine spreads, shortenings and whipped toppings.
Stress also stimulates colonic spasms in people with IBS. This process is not clearly understood, but scientists point out that the colon is partially controlled by the nervous system. Counselling is sometimes helpful for alleviating the symptoms due to IBS. However, doctors are quick to note that this does not mean IBS is the result of a personality problem. IBS is at least partially a disorder of colon motility.
How does a proper diet help IBS?
For many people, eating the proper diet helps lessen IBS symptoms. Before considering a change in diet, you should note whether any particular foods seem to cause distress and then discuss them with your doctor. If dairy products cause your symptoms to flare up, try decreasing the amount consumed at any one time. Yoghurt can also be a satisfactory substitute. Dietary fibre, present in wholegrain breads and cereals and in fruits and vegetables, has also been shown to be helpful in lessening IBS symptoms. Your doctor should be consulted prior to using an over-thecounter supplement such as Metamucil. High fibre diets keep the colon mildly distended, which helps to prevent spasms from developing. Some forms of fibre also keep water in the stools, thereby preventing hard, difficult to pass stools from forming. Doctors usually recommend that you eat just enough high fibre so that soft, easily passed, painless bowel movements are produced. Diets too may cause gas and bloating, however, over time these symptoms may dissipate as the digestive tract becomes used to increased fibre intake.
Large meals may also cause cramping and diarrhoea in some people suffering from IBS. Therefore, eating smaller meals more frequently, or eating smaller portions of food at mealtimes, especially if the foods are low in fat and rich in carbohydrates and protein may also alleviate symptoms. Foods high in carbohydrates and low in fat include pastas, rice, breads, cereals and fruits and vegetables. Foods high in protein and low in fat include chicken and turkey without the skin, lean meats, most fish and low fat dairy products such as skim milk and low fat cheeses.
Can drugs relieve IBS?
No consensus exists amongst doctors about the drugs to be used in treating IBS. Some doctors prescribe a combination of antispasmodic drugs and tranquilisers and these may relieve symptoms. Other physicians feel that first they should reassure patients and discuss means of controlling stress-inducing factors in their life situations. The variable nature of the disorder makes it difficult to conduct a well-designed clinical trial, which would help to establish the best form of treatment for IBS. The major concerns in drug therapy of IBS are dependency and the effects the disorder can have on lifestyle. In an effort to regulate colonic activity or minimise stress, some patients become dependent on laxatives. If this becomes the case, we generally try to withdraw these drugs slowly and use natural fibre instead. It is probably best to start with a fibre supplement like Metamucil or Benefibre and go from there. Some patients benefit from the bowel calming effect of Doxepin or Dothiepin. Treatment is always prescribed on an individual basis by Dr White.
Is IBS linked to more serious problems?
IBS has not been shown to lead to any serious organic diseases. There is NO link between IBS and Inflammatory Bowel Diseases such as Crohn’s disease or Ulcerative Colitis. IBS does NOT lead to cancer.