While stress doesn't CAUSE UC, it certainly does aggravate it if you have it, and yes, it can bring on flares, you're not imagining things. I'd give the Lialda a few more days then call your GI if your symptoms are still not improving.
What are you eating now? Stay away from "gassy" veggies, like broccoli, cabbage, peppers. Rice is usually "safe" for most of us, seafood, especially salmon, is a good protein source, most find avocado soothing. Everybody finds different things help or hinder, but those are almost universal. Avoid fibrous veggies, seeds, popcorn, that sort of stuff. Most people find coffee, decaf or regular, not manageable when in a flare.
Diagnosed UC April 27, 2006
Remicade infusions: 7/21/07; 8/18/07; 10/13/07; 12/15/97; 1/26/08; 3/8/08
Lialda, 4 tabs in the morning; Protonix; Prednisone 4/27/06-present, tapering attempt, down to 10/5 mg. alternating daily. Daily supplements: multivitamin w/folate; Culturelle; Fish oil capsules, calcium chews and/or Tums
12/1 - 12/29/07 weekly Venofer (iron) injections; <S>9 mg Entocourt EC</S>; Xanax as needed; Lexipro 10 mg, <S>Rowesa;</S> <S>Asacol; Colazal</S>; Bad reactions: Imuran (2/07)