The weirdest case I saw was one of the last managers I had at Globo Gym, a man entrusted with the job of disciplining me for "helping" members understand physiology as opposed to starvation diets or exercising personal draining. Mr X had seriously bad Crohn's, yet it was his lucky day sat opposite the company health geek, sat with some serious answers to his problems. Despite the disciplinary, I really did think that once he heard my simple explanation of his condition, and how we could work to overcome the Crohn's, that he would fight my corner for me. Sadly he wasn't interested, to this day I often wonder if he enjoys his time sat in various cubicles, sweating after just avoiding an another near accident!?
Anyhow, the biomarkers of IBS and in fact most other "itis" in the gastrointestinal tract, tend to show multiple tests that I do. So, I usually know that you suffer these conditions before you even tell me. I sometimes know you suffer them before you even know, especially if you've come from a paleo diet, or some other diet and exercise regime that increases cortisol and decreases immune function [1.2] Frequently I can see that people are on the verge of suffering with their"itis", or that their diet is masking issues just like steroids would. I can see it creeping up, and while it may not currently cause a problem, and I don't wish to be the prophet of doom, it is very naive to imagine that it occurs overnight.
References;
1. Tomiyama AJ, Mann T, Vinas D, Hunger JM, Dejager J, Taylor SE. (2010). Low calorie dieting increases cortisol. Psychosom Med. 2010 May;72(4):357-64. doi: 10.1097/PSY.0b013e3181d9523c. Epub 2010 Apr 5.http://www.ncbi.nlm.nih.gov/pubmed/20368473
2. Suzanne C. Segerstrom and Gregory E. Miller (2004). Psychological Stress and the Human Immune System: A Meta-Analytic Study of 30 Years of Inquiry. Psychol Bull.
Psychol Bull. 130(4): 601–630. doi: 10.1037/0033-2909.130.4.601 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1361287/