Thanks again, all, for the food advice for someone (me) who seemingly can't eat anything without ensuing carnage and pain. Even OTC medications were a no-no. From esophagus to large bowel, everything appears to have gone pear-shaped. (I'm early 60s, auto-immune everything, on biologics. Had scans, FIT, other faecal & blood tests and sigmoidoscopy to rule out obvious tumour. [I hope])
@TeaAndStrumpets Potatoes seem ok in small quantities - the advice is specfically no tomatoes because they are 'acidic'. Re meat: I used to be vegetarian but now I have to find protein where I can iykwim. However my guts don't seem able to digest meat very well. I can manage one egg or a small bit of poached fish a day.
DP has made me some some chicken broth though and I had some yesterday. (We'd buy it, but it's all got onion and garlic in. Sigh.)
He's also bought about 15 litres of Plenish oat 'milk' drink which doesn't have any oil or fat in it - just water, oats and sea salt; perfect for this weather. It's on offer at Tesco fortunately 
@MewithME I've got tinned fish and some tinned spinach in the cupboard. I've seen the nurse diet specialist at the GP, but she says she only really deals with diabetic dietary advice ('give up cheese') so couldn't really help. I need another Gastro referral for an endoscopy but my lovely named GP passed away unexpectedly at Xmas and I'm still with the 'locum team' still who are a bit hit and miss. I'll keep trying, but it'll be another series of waits, so meanwhile I just need a plan to stay alive and kicking as well I can.
@CoffeeBeansGalore Yes, I've got plenty of cold Activia yogurts, Kefir yogurt, Yakult and lactase tablets!
I also discovered advice online to sip bicarbonate of soda in a large glass of water throughout the day to counter the acid in my stomach that seems to be permamently overflowing. And I've got the electrolyle sachets! I used to work and live in the Near East so I'm ok in the heat.
I can't manage apple at all and loads of gluten-free products seem to have apple in them! Good shout on the rice noodles upthread, thanks.
It's soooooo boring for other people. I just need a 'set menu' for my day that I can stick to and my family know about.
Thank you all, you've helped me a lot. 