I would further evaluate the upper digestive tract to look at the extent of the possible fungal infection in the mouth, and to see how far down it spreads.
I do agree with your physician in that the CBC doesn't seem to be markedly abnormal.
At this time, an upper endoscopy can be considered. In addition to evaluating for oral fungal infection, it can also look for GERD, an ulcer, or inflammation of the upper digestive tract.
Another consideration would be imaging the abdomen with an ultrasound or CT scan.
These options can be discussed with your personal physician, or in conjunction with a GI physician.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin Pho, M.D.