What are the three sub-types of irritable bowel syndrome?

What are the three sub-types of irritable bowel syndrome?

Lin Chang (UCLA Division of Digestive Diseases) gives expert video advice on: What are the three sub-types of irritable bowel syndrome?; What are the symptoms of IBS with diarrhea?; How is IBS with diarrhea treated? and more...

The three sub-types of IBS, which is based on bowel habit, is IBS with diarrhea, IBS with constipation, IBS with mixed pattern-- meaning that the patients have both diarrhea and constipation within hours or days. So I can have IBS with diarrhea and go to the bathroom three times a week, but if every time I go I have loose watery stools, I'm going to be a diarrhea patient. Patients with constipation, they typically don't go very often, but if they go to the patient three times a day, or five times a day, because they never fully evacuate, but they have hard stools, they have constipation. They don't have diarrhea sub-type. The mixed pattern means that you change from loose watery stools to hard lumpy stools, or vice versa, within hours to days. The term IBS with alternating bowel habits, which is a term we used more before, we use that term when you transition between subgroups, so you transition over months to years from IBS with diarrhea to IBS mixed pattern or to IBS with constipation. Studies have shown that the mixed pattern group tends to go to the diarrhea side or the constipation side. It's pretty unusual to be pure diarrhea with IBS and transition to an IBS with constipation. It can happen, but it's much less common.