A Gastroscopy and a Colonoscopy

I'm going to have a gastroscopy and colonoscopy in two weeks. I've had the former once a year for 10 years, but It's the first time I've had the latter. The day before I'll go to the hospital, I have to take two tablets of laxative and I have to drink 1 to 2 liters of the laxative on the day until my colon is clean. A lot of people say the liquid laxative doesn't taste good. I'm looking forward to having a colonoscopy.