Why Is The Medicine Protonix Prescribed After Endoscopy?

I had an endoscopy and a colonoscopy. The doctor said I had some ulcers and some hemrroids up inside my rectm. He said I cannot have NSAIDS, Tylanol only. He also gave me a prescription for Protonix [I got the generic Pantorazole]. What does this medicine do. He never mentioned Colitis to me.