Table 1 The criteria for the diagnosis Irritable Bowel Syndrome according to the Rome II and III consensus

Rome II: At least 12 weeks, which need not be consecutive, in the preceding 12 months, of abdominal discomfort or pain that has two of three features:

Rome III: At least 3 months, with onset at least 6 months previously of recurrent abdominal pain or discomfort associated with 2 or more of the following:

(1) Relieved with defecation; and/or

(2) Onset associated with a change in frequency of stool; and/or

(3) Onset associated with a change in form (appearance) of stool.

Supportive symptoms:

1. Fewer than 3 bowel movements a week

2. More than 3 bowel movements a day

3. Hard or lumpy stools

4. Loose (mushy) or watery stools

5. Straining during a bowel movement

6. Urgency (having to rush to have a bowel movement)

7. Feeling of incomplete bowel movement

8. Passing mucus (white material) during a bowel movement

9. Abdominal fullness, bloating or swelling