IBS is a functional gastrointestinal disorder, characterised by diffused abdominal complaints, and an altered bowel habit and form of stool.
There is a strong correlation to mental or physical stress; complaints occur frequently after a severe bowel infection.
The diagnosis is a diagnosis by exclusion. The diagnosis is made if the symptoms can not be linked to other organic cause in spite of a careful examination of the patient (ultrasound, x-ray, endoscopy).
The diagnosis is made pursuant to the so-called ROME III diagnostic criteria:
- Improvement with defecation
- Onset associated with a change in frequency of stool
- Onset associated with a change in form (appearance) of stool
A colonoscopy is indispensable in order to exclude organic changes, particularly if alarming symptoms such as weight loss, blood in the faeces or signs of inflammation are present in the blood test.