Brief Answer:
It could be Acid peptic disease.

Detailed Answer:
Hi
Pain in the abdomen can be due to many reasons. The diagnosis depends on the site of the pain.
If it is present in the middle of the upper abdomen, It could be due to Acid peptic disease. If it is on the right side of the upper abdomen, Gall bladder stone has to be excluded.
Ask him to avoid spicy food,carbonated drinks, caffeine products. He should eat his regular diet at frequent intervals.
I prescribe Proton pump inhibitor like Rabeprazole to my patients with similar complaints.
If there is no response, I will go for Investigations like Upper GI Endoscope and Ultrasound abdomen.
Please consult your doctor and get him examined clinically.
Nothing to worry.
Hope I answered your query. If you have any questions, I will clarify further.
Wish you good health.
Regards

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