- The Cause of IBS -

IBS Explained (1.4MB PDF)
Everything you need to know about IBS.

Constipation - Causes, Diagnosis & Treatment

...a book written for the scientific community
which you may download for free.
Read the chapter;
'Irritable Bowel Syndrome & Constipation'
The original scientific paper;
The small intestine and irritable bowel syndrome:
A batch process model.
Medical Hypotheses (2008), 71:781-787,
Brian C. Dobson