Is It Safe To Take Antacids Before Getting Hydroscan?

I get a hydroscan tomorrow morning b/c of my gall bladder. I am in great discomfort today...it's gonna be a long one. I know I can't take any pain pills today. But can I take a few antacids or chew Tums before I attempt to eat today? I already hear the rumbles just from a few bites of plain yogurt.