Irritable Bowel Syndrome

What is irritable bowel syndrome?

Irritable bowel syndrome is a common condition related to the intestines (bowels). An estimated 10 to 20 percent of people in the general population experience symptoms of irritable bowel syndrome. In people with irritable bowel syndrome, the intestines squeeze too hard or not hard enough and cause food to move too quickly or too slowly through the intestines. Irritable bowel syndrome is usually present from the age of 20 and is more common in women.

Irritable bowel syndrome is also called functional bowel syndrome, irritable colon, spastic bowel and spastic colon. It's not the same as inflammatory bowel disease.

What causes irritable bowel syndrome?

There are a number of theories about how and why irritable bowel syndrome develops. Despite intensive research, the cause is not clear.

What are the symptoms of IBS?

• bloating and gas;
• mucus in the stool;
• constipation;
• diarrhoea, especially after eating or first thing in the morning;
• feeling like you still need to have a bowel movement after you've already had one;
• having a strong urge to have a bowel movement; and
• abdominal pain and cramping that may go away after having a bowel movement.

The symptoms may be triggered by certain foods and may worsen when you're under stress. Women who have irritable bowel syndrome may notice more frequent symptoms during their menstrual periods.

How is irritable bowel syndrome diagnosed?

The diagnosis is made by a doctor who will recognise the pattern of abdominal symptoms that you describe. The hallmark of irritable bowel syndrome is abdominal pain in association with altered bowel habits (diarrhoea or constipation).

If your symptoms have just started, something else may be the cause. Your doctor may need to do some tests, such as a blood test or colonoscopy, to make sure that your symptoms aren't caused by something other than irritable bowel syndrome.

How is irritable bowel syndrome treated?

Several treatments and therapies are available for irritable bowel syndrome. These measures help alleviate symptoms, but do not cure the condition. Treatment is often combined to reduce the pain and other symptoms of irritable bowel syndrome and it may be necessary to try more than one combination to find the one that is most helpful.

Treatment is usually a long-term process; during which it is important to communicate with your healthcare provider about symptoms, concerns and any stressors due to problems at home, work or family that develop. The best way to handle irritable bowel syndrome is to eat a healthy diet, avoid foods that seem to make you feel worse and find ways to handle your stress.

Why fibre may be helpful

Fibre can be helpful because it improves how the intestines work. There are two types of fibre:

• Soluble fibre helps for both diarrhoea and constipation. It dissolves in water and forms a gel-like material. Many foods contain soluble fibre, such as apples, beans and citrus fruits. Psyllium, a natural vegetable fibre, is also a soluble fibre. You can buy psyllium supplements to drink and you can add it to other foods.

• Insoluble fibre helps for constipation by moving material through your digestive system and adding bulk to your stool. Insoluble fibre is in whole grain breads, wheat bran and many vegetables.

Increase the fibre in your diet slowly. Some people feel bloated and have gas if they increase their fibre intake too quickly. Gas and bloating usually improve as you get used to eating more fibre. The best way to increase your fibre intake is eat a wide variety of high-fibre foods.

Do certain foods cause irritable bowel syndrome?

No, foods don't cause irritable bowel syndrome. But some foods may make you feel worse. Foods that may aggravate symptoms include foods high in fat or caffeine. Fat and caffeine can cause your intestines to contract, which may result in cramping. Alcohol and chocolate may also make you feel worse. If gas is a problem for you, you might want to avoid foods that tend to make gas worse. These include beans, cabbage and some fruits.

Keeping a diary of what you eat and your symptoms for a few weeks may be a good way to find out if a particular food triggers the onset of symptoms. If you think a certain type of food makes you feel worse, don't eat it. But don't cut out food unless it has caused you problems more than once.

What about milk and milk products?

If milk and other dairy products bother you, you may be lactose intolerant. Lactose intolerance means that your body can't digest lactose (the sugar in milk).

Dairy products may seem to make irritable bowel syndrome symptoms worse if you're lactose intolerant. If this seems to be the case, you may need to limit the amount of milk and milk products in your diet. Talk to your family doctor if you think you have trouble digesting dairy products.

How can stress affect irritable bowel syndrome?

Stress may trigger symptoms in people with irritable bowel syndrome. Talk to your family doctor about ways to deal with stress, such as exercise, relaxation training or meditation. He or she may have some suggestions or may refer you to someone who can give you some ideas. Your doctor may also suggest that you talk to a counsellor about anything that may be bothering you.

Can my doctor prescribe medicine for irritable bowel syndrome?

There is no cure for irritable bowel syndrome. However, if you're having bad symptoms, your doctor may prescribe medicine to help you manage or lessen them.

• Anti-cholinergic medication

Anti-cholinergic drugs block the nervous system's stimulation of the gastrointestinal tract, helping to reduce severe cramping and irregular contractions of the colon.

• Antidepressants

Many tricyclic antidepressants have a pain-relieving effect in patients with irritable bowel syndrome. The dose of tricyclic antidepressants is typically much lower than that used for treating depression. It is believed that these drugs reduce pain perception when used in low doses, although the exact mechanism of their benefit is unknown. Tricyclic antidepressants are generally started in low doses and increased gradually. Their full effect may not be seen for three to four weeks. Tricyclic antidepressants also slow movement of contents through the gastrointestinal tract and may be most helpful in people with diarrhoea-predominant irritable bowel syndrome.

• Anti-diarrhoeal drugs

These drugs can help slow the movement of a stool through the digestive tract and are most helpful in people with diarrhoea-predominant irritable bowel syndrome. However, doctors usually recommend that these drugs should only be used as needed, rather than on a continuous basis.

• Anxiolytic drugs

Anxiolytic drugs reduce anxiety. Anxiolytic drugs are occasionally prescribed for people with short-term anxiety that is worsening their irritable bowel syndrome symptoms.

Will irritable bowel syndrome get worse over time?

No, while irritable bowel syndrome will probably recur throughout your life, it won't get worse. It doesn't cause cancer or require surgery and it won't shorten your life.

Tips on controlling irritable bowel syndrome

• Eat a varied, healthy diet and avoid foods high in fat.
• Drink plenty of water.
• Try eating six small meals a day rather than three large ones.
• Learn new and better ways to manage your stress.
• Avoid using laxatives. They may weaken your intestines and cause you to be dependent on them.
• Although irritable bowel syndrome can cause pain and stress, the majority of patients are able to control their symptoms and live a normal life without developing serious health problems.

References

1. UpToDate

2. American Academy of Family Physicians