I take Prevacid for acid reflux at night, and I am having an endoscopy tomorrow. The written instructions say not to eat eight hours before the procedure, and it says it's okay to take heart medicine. But there is nothing written whether it is okay to take stomach medicine more than eight hours before the procedure. (It would be about eleven hours before the procedure now) I started searching online, and one site says you should not take any antacids the day of the test because it could interfere with the reading - but I don't know if I can take it the night before. Since I won't be allowed to drink water in a few hours, I won't be able to do anything for the heartburn then, so I wanted to take the medicine now, but not if it will interfere with my test later on. I got conflicting advice from my family, so I'm not sure what to do.