I did this post in reply to anothers but thought it may be useful to more people so am posting it here as well, hope it helps.
I have been studying diet for the last 6 years, after my operation and have been working with the hospital dietician and others to get to the bottom of how diet influences my state of health. I would reommend going down this path as it has resolved many of my issues. By changing my diet I have eliminated many of the problems seen on these pages and by understanding the microbiom, (the bacterial flora in the gut) and it's relationship to health you get a better understanding of how this all works.
Be aware that many doctors do not study this area and so will not point you in this direction but I firmly believe that the many of the gut problems we experience come from not understanding and managing our digestive system well. Please do your own research but a good place to start would be taking a look at the Cancer active website set up by Chris Woollams, I was first directed to this site by the cricketer Geoff Boycott who gave a talk at the Nottingham OPA (Oesophageal Patients Association) about his own journey with cancer, he said he had access to all the experts that money could buy but found this the best source of information about cancer and how to beat it. I looked because of his recommendation and found a wealth of information that has helped me a lot