What is irritable bowel syndrome?

Irritable bowel syndrome (IBS), also known as spastic colon, is a common condition affecting the intestines and bowel. It is characterised by a number of uncomfortable symptoms including bloating, cramps, heartburn, diarrhoea and constipation. While it is troublesome and can cause great discomfort, it is not life-threatening - it is not related to cancer and does not cause permanent damage to the bowel.

It is estimated that 15 percent of people in western countries are affected by IBS. For reasons unknown, women are twice as likely to be affected as males.

What causes IBS?

IBS is a complex condition for which there is no known cause. However, many doctors now agree that symptoms can be triggered by psychological as well as physical factors.

Normally, food passes through the stomach, the small intestine and the large intestine (the colon) by means of regular muscular contractions. In IBS, however, the normal rhythm of intestinal contractions is disrupted, resulting in diahorrea, constipation and intestinal spasms.

The bowel in people with IBS also appears to be more sensitive than usual and an attack may be triggered by certain foods that would not bother most people. This also offers some explanation as to why symptoms are exaggerated after eating. Some sufferers have pinpointed dairy products, caffeine and alcohol as triggers but you should try to find your own individual triggers.

Stress and hormonal changes have also been named as familiar culprits.

What are the typical symptoms?

Symptoms may present in early adulthood and are generally recurrent. Some people suffer intermittent flare-ups that may worsen in times of stress. Symptoms may range in severity and include:

• Abdominal pain: cramp-like pain that can last minutes to hours. Emptying the bowels may bring some relief. The pain onset may be associated with a change in the frequency and appearance of the stool.
• Excessive gas production.
• Bloated feeling.
• Swelling of the abdomen.
• A sensation of incomplete evacuation.
• Presence of mucus (yellowish streaks) in stools.
• Diarrhoea or constipation. Sometimes an alteration between the two.
• Other symptoms may include non-cardiac (non-heart) chest pain and heartburn.

The following symptoms point towards other conditions and not IBS:

• Symptoms beginning in the elderly.
• Bleeding from the back passage.
• Weight loss.
• Bowel obstruction.
• Passage of large volumes of loose, bulky stools.

Is there a test to diagnose IBS?

Diagnosing IBS can be difficult as there is no distinct laboratory test available to diagnose the condition. Your doctor will take a history, inquiring in detail about your symptoms to rule out other conditions that resemble IBS such as crohn's disease and ulcerative colitis.

An examination will also be performed. The examination usually shows no abnormality, although there may be some tenderness noted in the abdomen.

Blood tests may be taken to rule out anaemia. Stools are tested for blood.

In some cases, a camera test called a sigmoidoscopy may be undertaken to look at the lower part of the large bowel. This helps identify any inflammation.

Other tests may include x-rays of the bowel or more extensive camera tests of the large bowel (called a colonoscopy)

If you suspect you have IBS and are experiencing pain, it is wise to make an appointment to see your doctor.

How is IBS treated?

People with IBS may require no treatment at all. But medication is available for those that are quite troubled by symptoms of constipation, diarrhoea and abdominal pain.

• Increasing the amount of fibre in your diet or taking fibre supplementation may help to ease the discomfort of constipation. Dietary sources of fibre include whole grain breads, cereals, beans, fruit and vegetables. However, for some sufferers, fibre actually worsens their symptoms. If this is the case, fibre may have to be withdrawn from the diet.

• The routine use of strong laxatives is unwise as diarrhoea can result as a side effect.

• Keep a diary of the foods that seem to trigger symptoms and eliminate them one by one to see if it helps ease your symptoms. However, before changing your diet it is best to discuss the situation with your doctor. There is little scientifically valid information on the relation of diet to IBS.

• If diarrhoea is the predominant feature of IBS then anti-diarrhoea agents may be used.

• Anti-spasmodic agents such as propantheline and hyoscine help relieve crampy abdominal pain. However, these drugs can cause blurred vision and dry mouth. They are not recommended in those with glaucoma or an enlarged prostate.

• Smooth muscle relaxants such as alverine, mebeverine also help relieve the spasm.

Side-effects include nausea, headache, itching of the skin, rash and dizziness

• Peppermint oil gives relief of abdominal colic and distention but may cause heartburn. Peppermint oil capsules such as Colpermin are readily available at your chemists.

• If your symptoms are provoked by stress, take steps to reduce the amount of stress in your daily life. Join a gym, take up yoga or meditation or book yourself in for a nice relaxing massage. For more advice see our top ten tips for destressing.

Written by Medpages Editorial Team
Last Editorial Review: 18/1/2010