Dear friend, welcome to HCM!
It is unlikely a costochondritis
without rib tenderness.
Does he have heartburn
, sour eructuations, back pain, chest / upper abdominal discomfort/pain?
Are the symptoms more when lying down?
Does he smoke? Are there any other symptoms?
Is a CBC done? any allergies?
It could be 'many things'.
could also cause this (dyspepsia
Please describe the symptoms in great details to be able to give you a more specific advice.
Take care and please keep me informed of your progress.
I hope to have answered your query satisfactorily.