Irritable bowel syndrome

What is irritable bowel syndrome (IBS)?

Irritable bowel syndrome (IBS) is a collection of symptoms that an individual may develop. The most common symptoms of IBS are abdominal pain or discomfort  (cramping, bloating, gas), diarrhea, and/or constipation. IBS affects the colon, or large bowel, which is the part of the digestive tract that stores stool. IBS is not a disease as such and by definition the bowel is normal in appearance. The syndrome seems to result form a heightened sensitivity to sensory information from the gut’s sensory nervous system.

What causes IBS?

Doctors are not sure what causes IBS. The nerves and muscles in the bowel appear to be extra sensitive in people with IBS. Alternatively the central nervous system may “handle “ sensory information differently in patients with IBS. The gut is one long muscular tube that contracts continuously. In the fasted state. a spontaneous contraction (migrating motor complex-MMC) occurs in the duodenum and migrates down through the gut’s entire length about every 90 minutes. In response to food (fed state), these contractions occur much more readily. The consequent pressure changes in the gut lead to sensory nerves being stimulated in the gut wall. This sensory information is relayed centrally along sensory nerve fibres. In people with IBS increased awareness of this sensory nervous “traffic” leads to the experience of pain

Although IBS can be painful, by definition, it does not damage the colon or other parts of the digestive system. IBS does not lead to other health problems.

What are the symptoms of IBS?

The main symptoms of IBS are;

Abdominal pain or discomfort in the abdomen, often relieved by or associated with a bowel movement

Chronic diarrhea (diarrhoea predominant IBS), constipation (constipation predominant IBS), or a combination of both.

Other symptoms are;

Passage of pale mucus in the stool, swollen or bloated abdomen,ensation of incomplete emptying of the lower bowel.

In women with IBS symptoms may worsen during a menstrual periods.

How is a diagnosis of IBS established?

The doctor may suspect that you have IBS because of your symptoms. Specific symptoms, called the Rome criteria, can be used to make sure you don’t have any other health problems that may cause similar symptoms.

Investigation for people with IBS;

In addition to a physical exam and blood tests, the following tests might be done to diagnose IBS:

Colonoscopy; For this test the doctor inserts a long, thin tube, called a colonoscope, through the anus and up into the colon. The doctor can view the inside of your colon and take specimens if required.

What is the treatment for IBS treated?

IBS has no cure, but it maybe possible to relieve symptoms. Treatment may involve establishing whether fundamentally you have a slow, normal or fast gut. Treatment will be guided by this assessment and may involve:

Dietary changes


Stress relief

You may have to try a few things to see what works best for you. Your doctor can help you find the right treatment plan.

Dietary Changes

Some foods and drinks make IBS worse.

As IBS seems to relate to an increased awareness of gut contractility it is a characteristic of IBS that symptoms are usually exacerbated by food. However it is difficult to be too prescriptive about die as clearly different food classes affect different people.

Foods and drinks that may cause or worsen symptoms include;

Fatty foods, like French fries

Milk products, like cheese or ice cream



Caffeinated drinks, like coffee and some sodas

Carbonated drinks, like soda.

These foods may make IBS worse.

To find out which foods are a problem, keep a diary that tracks

What you eat during the day

What symptoms you have

When symptoms occur

What foods always make you feel sick?

Take your notes to the doctor or dietician to see if certain foods trigger your symptoms or make them worse. If so, you should avoid eating these foods or eat less of them.

 Some foods may make IBS better.

If you have constipation predominant IBS (slow bowel), taking measures to improve constipation may help other IBS symptoms as well. Fibre may reduce the constipation associated with IBS because it makes stool soft and easier to pass. However, some people with IBS who have more sensitive nerves may feel a bit more abdominal discomfort (bloating) after adding more fibre to their diet. Fibre is found in foods such as breads, cereals, beans, fruits, and vegetables. Generally, soluble fibre (e.g. kiwis, prunes and apricots) are felt to be gentler that insoluble fibres such as brans and cereals.

Examples of foods with fibre include



Breads, cereals, and beans



Broccoli (raw)


Carrots (raw)


Kidney beans

Whole-grain bread

Whole-grain cereal

Add foods with fibre to your diet a little at a time to let your body get used to them. Your doctor may ask you to add more fibre to your diet by taking a fibre pill or drinking water mixed with a special high-fibre powder.

Eat small meals.

Large meals can cause cramping and diarrhea in people with IBS. If this happens to you, try eating four or five small meals a day instead of less-frequent big meals.


The doctor may give you medicine to help with symptoms.

Laxatives treat constipation. Many kinds of laxatives are available. Your doctor can help you find the laxative that is right for you.

Antispasmodics control spasms in the colon and help ease abdominal pain.

Antidepressants, even in lower doses than are used for treating depression, can help people with IBS. They can help reduce the abdominal discomfort or pain associated with IBS and, depending on the type chosen, may help the diarrhea or constipation.

Another drug is sometimes prescribed for the treatment of IBS. Loperamide is often used in people with severe IBS whose main symptom is diarrhea (Diarrhoea predominant).

You need to follow your doctor’s instructions when you use the medicine. Otherwise, you may need to keep taking it in order to have a bowel movement. Talk with your doctor about potential side effects and what to do if you experience them.

Does stress cause IBS?

Emotional stress does not cause IBS. But people with IBS may notice their bowels react more to stress. So, if you already have IBS, stress can make your symptoms worse.

Stress Relief; learning to reduce stress can help with IBS. With less stress, you may find you have less cramping and pain. You may also find it easier to manage your symptoms. Meditation, relaxation classes exercise, hypnosis, and counseling may help. You may need to try different activities to see what works best for you.

Points to Remember

IBS can cause cramping, bloating, gas, diarrhea, and constipation.

IBS doesn’t damage the bowel or lead to other health problems.

The doctor will diagnose IBS based on your symptoms. You may need to have medical tests to rule out other health problems.

Stress doesn’t cause IBS, but it can make your symptoms worse.

Fatty foods, milk products, chocolate, alcohol, and caffeinated and carbonated drinks can trigger symptoms.

Eating foods with fibre and eating small meals throughout the day may reduce symptoms.

Treatment for IBS may include medicine, stress relief, and changes in eating habits.

Other sources of information:

Irritable bowel syndrome in adults. NICE clinical guideline 61 (2008). Available from:

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