As a Naturopathic Doctor in Toronto, I see lots of people diagnosed with Irritable Bowel Syndrome. It's often a frustrating diagnosis, as it largely means that you have a set of symptoms but that things appear normal when medical testing is done. I became a Naturopathic Doctor after receiving a diagnosis of Irritable Bowel Syndrom, and not receiving any help in how to manage this condition. Luckily I started seeing a Naturopathic Doctor myself and it was obviously life changing!
There are many factors that can contribute to IBS, one of the major ones being stress. I try to take a multi pronged approach in treating IBS, from dealing with stress, watching for foods that are aggrevating digestive symptoms, to strengthening the digestive tract so that it becomes less reactive.
I really hate eliminating foods from a persons diet, and try to avoid it as much as possible. But I will admit when a patient isn't responding to treatment as I expect, I will pull out the FODMAP diet. Fodmaps are Fermentable Oligosaccharides,Disaccharides, Monosaccharides And Polyols (i.e. fermentable short-chain carbohydrates). Research shows that if not properly digested these foods pull water into the intestinal tract which can cause diarrhea, as well they can ferment in the small intestine creating gas & bloating. Some studies have shown that over 70% of people who use a low FODMAP diet have improved IBS symptoms. Reducing FODMAPs includes avoiding many fruits & vegetables, dairy, legumes, and gluten. As I said, because it is quite restrictive, I try other things to manage IBS rather than jumping right to the FODMAP diet - but when I'm stuck and have suggested, it's often helpful!