You're right to be concerned, as anyone should be if they're passing blood, but there may be some simple causes.

Although IBS doesn't usually cause bleeding, there are other conditions linked with IBS, such as haemorrhoids (piles) or cracks in the anal passage, that could cause it. These are more likely if you're having to strain to open your bowels, or going very frequently, as you do in IBS. So your IBS could be the reason.

But there are other serious causes of passing blood - particularly bowel cancer - and this must be ruled out. Always see your GP if your normal toilet habit changes, or if you pass blood or mucus.

Specialist tests

The specialist may simply ask you to test one of your bowel movements to see if you're still bleeding. It's more likely he or she will do a camera examination (called an endoscopy), where a telescopic camera is passed into the bowel to examine its inner lining. Or you may have a test called a barium enema, where a special dye is put into the bowel and X-ray pictures taken.

Neither of these tests should be painful, but both can be uncomfortable and may make you feel embarrassed. Remember hospital staff perform these procedures every day.

Other important symptoms

Your other symptoms (diarrhoea and stomach ache) could be explained by IBS (both typical of the syndrome), but also by other conditions such as diabetes, which can cause diarrhoea if severe.

Symptoms such as diarrhoea and stomach ache can also be signs of bowel cancer. Other worrying signs include weight loss, appetite loss and fatigue.

Try not to worry, get specialist advice and hopefully you'll get an explanation for your symptoms.

This article was last medically reviewed by Dr Trisha Macnair in March 2008