They should be able to tell from a B12 and iron count if you were bleeding internally. I had a friend who kept a very low B12 and somewhat low iron and finally got the endoscopy done and she has a severe peptic ulcer. She is on shots daily for B12, it was that low.
If the doc can do a CBC, he should be able to do the B12 and iron tests.
I have hypothyroidism (1953), diabetes type 2 (1976), high cholesterol (1989), gastroparesis (1990), FMS (1995), and GERD (2006).
Meds for FMS: Prozac, Xanax, Diclofenac, Cytotec (stomach med to go with Diclofenac), Lortab.
Other meds: Nexium, Cytomel, Detrol, Reglan, Novolog insulin, Novolin N insulin, Bumex, Lipitor, WelChol. Also on B12 sublingually, magnesium, Centrum Silver Vitamin, CoQ10.