I too have UC and Epilepsy, had both since 1979.
As Darren said, they are both stress related and go hand in hand.
Most important for you to know, I had my Colonoscopy just last week. (3rd one) No seizures or anything like that. As Darren also mentioned, it is very routine, no pain ~ just a little uncomfortable. If they find polyps in their, they remove them at the time, and take biopsies along the way. As I said before ~ no pain but you may feel some slight pulling.
They don't sedate you completely but you are totally relaxed.
The worst part is the preparation the day before when you have to drink 4,000 ml of that stuff (dont know what it's called) but it takes like CRAP, to clean you out.
It's mind over matter.
As you are drinking that "stuff" pretend that you're on a tropical island and you have one of those tropical drinks with the umbrella in it.
MAKE SURE YOU'RE NEAR A BATHROOM at all times.
Nothing to get freaked out about. (you dont want to stress it or you run the possibility of triggering a seizure)
Diagnosed with Epilepsy & Ulcerative Colitis.
Current Medications: Diantin 275mg, Pheonobarb 150mg, Asocol 3,000 mg.