Hi....what you're having is definitely a symptom of a flare and what I would classify still limited to the rectum...lower usually,but once it's a bit higher, diarrhea is a symptom, which seems to make it so much easier to expel.
Anyone with UC could have small intestinal problems not related to UC..but UC isn't into the small intestine unless there's a bit of backwash from pancolitis.
Your symptoms to me seem limited to the lower intestine, and the bloating and butt straining are definitely the worst.
You do need rectal meds to help with those symptoms and maybe eventually you could possibly try Asacol in place of the Colazal since it's no longer an option.
As well, ask the doc if he could prescribe a mild antispasmodic like dicyclomine to help with the spasming in the rectum and in the gut from the gas. It does help me...but I also use rectal meds to deal with flare symptoms...which does take a few days to notice an improvement.
You've definitely been through a very tough time, hope you'll improve soon.
There is always a possibility for misdiagnosis and you could have CD, but you will find out where to go next when you see the doc on Thursday.
Did you get the results already from the colonoscopy biopsies?..as per your comment regarding no dysplasia.
Welcome to the forum...
quincy.