IBS may be sub categorized into 3 according to people’s stool characteristics.

1. Constipation-predominant IBS
   People who have Constipation-predominant IBS have the following symptoms.
   a) Stomach pain and discomfort
   b) Bloating
   c) Abnormally delayed or infrequent bowel movement
   d) Lumpy/hard stool2. Diarrhea-Predominant IBS
   The symptoms are,
   a) Stomach pain and discomfort
   b) An urgent need to move bowels
   c) Abnormally frequent bowel movements
   d) Loose/watery stool
   3. IBS with alternating constipation and diarrhea

There are about an equal number of people with IBS in each category. There is also evidence that most people with IBS will alternate between types over time.