Yes, I concur with the suggestions here. You need to mention this to the doctor and to have flagyl side effects ruled out. However, you also need to have a full blood work-up to have iron, potassium and B12 levels checked. But make sure your magnesium levels are also checked. Tingling can be caused by low magnesium as well, and magnesium deficiency is quite common with UC or in fact any prolonged diarrhea.
You should also ask your doctor to check your thyroid levels.