Personally I think gastroenterology is a bit gross- too much talk about vomit and faeces for my liking. I used The Oxford Handbook of Clinical Medicine to make my notes and essentially included everything from mouth to anus plus all the bits coming off the digestive tract (liver, gall bladder, pancreas etc).
The videos I made are here:
GI Medicine I: oesophagus and stomach
GI Medicine II: the intestines
GI Medicine IV: the bile duct, gallbladder and pancreas (+ misc. other GI pathologies)
The notes are here:
There are also some additional bits and pieces here: GI additional notes