From my personal experience as well as a lot of study and professional counseling as well, I think the connection is indisputeable..though in many cases its sort of an chicken or the egg sort of thing...anxiety begets IBS, or IBS begets anxiety????...They feed off of each other. If a person was not prone to the syndrome, perhaps a single or short series of digestive phenomena might not recur if their was no propensity for clinical anxiety. Similarly, a person with a propensity for anxiety can easily start a sequence of symptoms that will self perpetuate into a syndrome of symptoms. I have always believed that anxiety "knows" what scares you and it knows how to pull your strings...it is capable of creating or simulating virtually any physical symptom and in many cases actual somatic pathology. Just my theory though....