First off - welcome and I'm sorry you're needing to join us!
It sounds to me as if you're eating the most basic, unlikely-to-irritate foods (although we all have different things that bother us.) So - good work on that!
I've never had a GI suggest Immodium. My son's GI recently said that he could take one, once in a while, if needed because of a special event. And.. that's pretty much what I've heard. I had understood that it was dangerous for people with UC to take Immodium on a regular basis because it would be dangerous - as your intuition told you - to block up a fragile colon. There is a rare but really dangerous condition called "toxic megacolon" in which the colon - well, becomes toxic and mega-inflamed, and we want to avoid anything that might promote that.
The biopsies from your colonoscopy will tell is you have UC or some other condition. Even if it is UC, sometimes Flagyl is prescribed to calm it down - there was a thread about this a few days ago.
Some of us respond well to probiotics..... I find they seem to help me. Also, I find Metamucil helps bulk up my stools while at the same time making them easy to pass.... but if you've not taken fiber before, I'd start that carefully (with a tiny dose) in case it's hard on your system.
If you tolerate dairy, yogurt might be good.....some folks here find spinach and sunflower seeds (or maybe butter) help.... any kind of nut butter could bring you good nutrition.... just trying to think off the top of my head here.
Hang in there, stay hydrated, and let us know how you're doing!
Age 54. Diagnosed UP 1983, Azulphidine
Diagnosed UC 1986 Prednisone almost 2 years
Asacol - 16 pills/day, cortenemas, Rowasa
Metamucil - 2 doses/day since '86, and psyllium seed powder
VSL#3DS, Multivitamin, Calcium and D
homemade yogurt each day
Ryzolt for arthritis pain
Son, 16, dx pancolitis 2007