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.
Identification
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.
Effects
While running can help produce regular bowel movements and contribute to lower risks of colon cancer, it can also unmask IBS. IBS is not caused by running, but a pre-existing condition can be revealed. IBS and its accompanying symptoms typically occur during or after running. Up to half of all runners suffer from general abdominal discomfort, including IBS. The up-and-down motion of running naturally stirs the bowels, while blood flow during running is diverted from the intestines to the legs, thereby opening the possibility of cramping or diarrhea.
Dietary Help
Avoiding certain kinds of food is important to IBS sufferers. For runners, choosing other kinds of food is just as critical. Most runners agree that loading up on carbohydrates can provide the energy needed to complete a run. High-carb foods such as rice, pasta, oatmeal, potatoes and white bread contain high soluble fiber content that is easy on the intestines. Caffeine, dairy products, and high-fiber foods can enhance IBS and should be avoided by frequent sufferers.
Medicinal Treatment
While there is no cure for IBS, runners can learn to minimize the symptoms with certain types of medicine. Fiber supplements or laxatives have been found to help those who particularly suffer from constipation. Many over-the-counter medications can alleviate diarrhea. Antispasmodics are commonly prescribed for dealing with colon muscle spasms and abdominal pain. It is important to carefully consider a medication, since a product prescribed to treat one symptom can actually spur a different one.
Prevention/Solution
Runners who suffer from IBS can try a number of preventative measures to make the experience of running a pain-free, pleasurable one. Avoiding food at least two hours before running will help minimize the risk of a full stomach triggering the condition during a run. Staying well-hydrated by drinking plenty of fluids before and after running is an effective approach to staving off symptoms. Run routes that include close proximity to public restrooms in case of emergency; for races or special events that do not include toilets, taking a pre-run anti-diarrhea medication can be helpful as well.
Well… that is all true. But it is really much easier to read than do. And not eating two hours before running doesn’t work… At the moment I’m have my 3rd stint with IBS. 1st time when I was diagnosed back in 2012 is lasted just over month. Medications helped and I was able to keep IBS at the bay for next almost 3 years. On some stage was doing that just with diet, no drugs. Was ok till December 2014. Two rough months. Drugs back and after that situation was under control. But now, third time is the worst. Already 4th month in and it is not going away. I know that with each new ‘return’ sickness will be worse. And that how it is now. Really bad. Medications not helping… visited doctor last week and got new drugs. Started on these last Sunday and should see effects in two weeks (one week in and can’t see improvements)… So, for now wait. Maybe new drugs will work. But if not… if not… I will think about that later. Ohhh… and it is ulcerative colitis really in my case but still calling and wishing it would be IBS just.