Colonoscopy in 5 hours. not supposed to drink anything after midnight. is it normal to feel thirsty? does this mean i'm dehydrated?

Colonoscopy, thirsty: Some patients will feel thirsty during the process of bowel preparation for the colonoscopy, a sign of dehydration. Normally, you can still drink liquid up to 2 hours prior to colonoscopy. However, some anesthesiologists are very strict with npo status. You might want to call to verify with the surgical center where you are going to have a colonoscopy.