this brief question sounds as if he has an H. pylori infection...his GP has been treating with, first, antacids then PPI's feels better for a short period but then resumes symptoms...should ask patient to see his physician and ask for further lab work up...you might even write some tests on your napkin (CBC, CMP, H.pylori IgG/IgM, amylase, Lipase)and give it to this person, then you could ask what he does and start asking him questions regarding his work. Tricky question as you know the therapy but what are they (USMLE) looking for. ethics, therapy, or long term health....Hmmmmmm