whats meds has he been on
for acid reflux? With the lesion in the stomach is sounds like
gastritis, but what caused it is the real question.
If Buscopan seems to work, he has to remember to take it consistantly.
Other than that, I'd maybe suggest getting a food allergy test done. Its possible he has an allergy to something he is eating on a daily basis. Those things pop up out of nowhere.