I have found short article by Lee Simmons about IBS and running on LiveStrong website – Running & Irritable Bowel Syndrome.
Running & Irritable Bowel Syndrome
Irritable bowel syndrome, or IBS, is a painful condition that affects the large intestine and can be especially pronounced among runners. Running places a certain amount of stress on the bowels and in some cases can reveal underlying symptoms caused by IBS. Fortunately, runners can use a number of preventative measures to keep IBS at bay while pounding the pavement on a regular basis.
The effect of IBS on the large intestine can produce a number of symptoms, including cramping, abdominal pain, constipation diarrhea, and bloating gas. IBS does not permanently impair the intestine like other diseases such as Crohn’s or ulcerative colitis. The condition is limited to its basic symptoms and does not lead to inflammation or changes in bowel tissue.Identification