Irritable bowel syndrome (IBS) is a very common condition, but in some ways it is still a mystery. There are many different theories about what causes the syndrome, and different doctors will give you different reasons for your illness ? anything from stress to bad bacteria to food intolerance. And once you have been diagnosed, there is no set form of treatment ? instead, sufferers tend to try two or three supplements or therapies to find a combination that works for them.

IBS is clearly a complicated issue, so here is a basic overview of the symptoms, diagnosis and treatment of this disorder.

The symptoms

Although the symptoms of IBS vary from person to person, there are several symptoms which are typical of the illness. The most common symptom is either recurring diarrhea or recurring constipation (although some patients also have alternating diarrhea and constipation).

Additional symptoms can include stomach pain (sometimes relieved by a bowel movement), bloating, nausea and a lot of gas. These symptoms generally go away for a short time before returning again, as IBS can work in cycles. Sufferers may experience a few weeks or even a few months of good health before the symptoms come back.

Sufferers sometimes find that their symptoms begin after a bout of food poisoning or an operation. Others date their symptoms back to a very stressful period in their lives, and some patients can see no clear reason for why their symptoms began.

The diagnosis

There is no set test for IBS, and it is often called a diagnosis of 'exclusion'. This means that a doctor may rule out other bowel and stomach complaints such as celiac disease or inflammatory bowel disease before giving you a diagnosis of IBS.

Sometimes patients are given a colonoscopy, where a tiny camera is inserted into the intestines to look for abnormalities. In an IBS sufferer the colonoscopy won't detect any physical signs of disease ? IBS is often called a 'functional' disorder, because it seems to be caused by an alteration in the way the body functions rather than an identifiable cause such as inflammation.

However, this does not mean it is any less real than, say, inflammatory bowel disease, it just means that doctors haven't come up with a proper test for it yet!

It is very important that you receive a diagnosis of IBS from a medical professional rather than self-diagnosing, as bowel symptoms can be present in many other health conditions.

The treatment

The first stage of treatment may involve any medications your doctor has given you to try. This could be an anti-spasmodic, which will relax the muscles in the gut walls, or perhaps a low dose of an anti-depressant, which can help to reduce the pain.

You may also be given one of the new drugs specifically developed for IBS ? Lotronex for diarrhea sufferers and Zelnorm for constipation sufferers.

If the drugs do not help you then you could try using a fiber supplement such as Citrucel to add bulk to your stool ? this can be helpful for both diarrhea and constipation. Also, there are other supplements such as Caltrate Plus which may be useful (Caltrate Plus contains calcium carbonate which can reduce diarrhea).

It may also be worth looking at your diet. A nutritionist can advise on ways to identify any particular food 'triggers' which may be setting off your symptoms, and also on whether you might have a food intolerance to something like gluten or lactose.

Finally, there are several alternative therapies which can be effective for IBS. Hypnotherapy has proved very effective, and a special form called gut-directed hypnotherapy has been developed just for digestive problems. Acupuncture may also be worth looking into.

Sophie Lee has had IBS for more than 15 years. She runs Irritable Bowel Syndrome Treatment http://www.irritable-bowel-syndrome.ws where you can read descriptions and reviews of the treatments available for IBS, from drugs to alternative therapy.