?? I can certainly understand your fear. I did not go into hospital but had a major intestinal problems with pretty much same symptoms as acute colitis in week 2 of my 1st round (last week).
I am seeing a Gastroentorologist tomorrow to discuss what happened as for 6 days I was unable to walk for more than 10 steps without massive intestinal pain and needing to rush into the loo.
Yesterday was the 1st day where I a tiny bit of relief and today actually managed to go for a long walk - just over an hour. I was so proud of myself but then as soo as I got home the now familiar pain hit and off to the loo I went.
I am due for my 2nd round in a week's time (Monday) and same as you dealing with an almost paralysing fear of the repeat of this problem or even a worse on as my gut has not healed.
I will be asking them to get me to see a dietitian to see if I can get some advice on diet during the 1st week as also thinking maybe I contributed due to what was a high fibre diet...
Sorry I cannot help you in figuring out what to expect but what was helping me was going on a very plain / bland diet that does not irritate the gut (baked potatoes, rice, plain white bread, clear chicken soup, bananas...)
All the best
Jel