I have had a diagnosis as to my health problems. For those who aren't interested about my 'inner workings' - here's a metaphorical GIF for you :-D
The procedure was * ahem * interesting. Moviprep is like drinking Flash floor cleaner and I had both endoscopy and colonoscopy done (not at the same time - so, no channel tunnel jokes purlease). Lest said about the actual procedure the better, except there are more pleasant ways to spend an afternoon.
I have been confirmed as the following: primary - IBS with lactose intolerance, diverticulosis in several areas; secondary - hiatus hernia (already knew that 25 years ago - barium meal ugh!) oesophigitis and gastritis. So relief that there aren't any other probs like coelitis, Crohn's or nobbly tumours etc. They are sending biopsies off for a better reading, but it appears that the digestive tract is inflammed and I am producing too much bile.
Need a total overhaul of my diet (no surprise there - several tonnage has to be lost), but also medication such as Proton Pump Inhibitors (omeprazole or similar) and I can't take aspirin or neurofen anymore - not that I did much anyway.
At least I can breathe out - I will get a list of recommendations etc., pending any other results :-D