My guess is they will do an upper GI (endoscopy) and find a gastritis based on the affect the meds had on your stomach lining.
Expect an hour long wait in the waiting room lol...fill out some forms..blah blah blah
the doctor will meet with you and ask why you are there. you will tell him
he may order some blood tests for seliacs...may order some stool camples for parasite...may order an ultrasound of the abdomen to check gallbladder function
he may screw all that stuff and say he wants to go for the colonoscopy/upper gi....i had a doc who said that..but i got scared of the procedure and never went ..and switched doctors who now wants to di it...ive eben suffering from issues for 6 years dont be like me.