This isn't about her disease. She specifically mentions wanting/missing fried bacon (and presumably also sausage, since those are also traditionally part of a full english), which are both terrible foods to eat with UC.

If she'd asked for white bread and baked beans, that would make more sense and be suitable for UC, but bacon ain't it. She's just a karen who's using her disease as an excuse to bitch about not getting what she wants.

White rice, fish and cooked vegetables, which are at least some of the food she was complaining about, are conversely actually an excellent meal for someone with UC