My gut health is a fucking train wreck. It's been a long hard road to get a solid diagnosis, but so far traditional medicine has been fucking useless with regards to diet/treatment.
I've Celiacs disease that I have lived with for ~10 years, zero gluten in my diet.
Suffered from Candida fungus over growth though my whole GI that I've solved with high dosage of cow Colostrum tablets. Killing fungus in your GI releases toxins, felt like I was living out the Trainspotting cold turkey scene for a weekend. Before killing the fungus, I was unable to eat ANY sugars without issues.
The big one is Permeable gut syndrome. Aka Leaky gut. Induced by pushing myself for 4-5hrs on the bike with no/not enough carbohydrate replenishment I believe on mega hot days.
A Systematic review has just been release looking into extreme exercise events causing gut issues.
http://onlinelibrary.wiley.com/doi/10.1111/apt.14157/full
And to top it all off, I've Diverticulitis of the large intestine. I started asking the Gastroenterologist the how/what/why questions and he told me "sorry, I'm just the plumber". GP wanted to send me to the psychologist.
I joined a leaky gut support group on Facebook of about 12,000 members, has been the most help so far.
I ate my first Potato last night in 9 months, and so far seem to be ok.