I'm having my first colonoscopy and my eighth or ninth endoscopy tomorrow. Since this is my first colonoscopy, this is the first prep that I've had to do. I have the HalfLytely prep for this time. I took the pills about 3 hours ago and I am miserable. I have already been to the bathroom 3 or 4 times and I have horrible pain and cramping. I feel like I'm going to throw up and I have extreme heartburn. Anybody else have symptoms like this? I know that it will only get worse after I have to drink the solution later tonight.