The colon is effected by running, its called runners d of course.In IBS the colon can be overactive to begin with.You might want to read this thread. http://www.ibsgroup.org/ubb/ultimatebb.php...ic;f=1;t=039609 I played soccer for twenty years and was going pro, until I blew my knee out. Even with severe IBS I played. Partof that was distraction while playing and over coming it in the first place. Oddly I did not get runners d all that often. I was pain predominate and alternating c and d, but more d then c.The best approach to IBS is treating the mind body connection in IBS, most people improve.