Hi there...abdominal pain could be due to several reasons like gastritis, pancreatitis, hepatitis,
kidney stones. From the history it looks he is suffering from gastritis. There will be no findings on ultrasound in case of gastritis. He will need to follow a healthy diet. Avoid spicy foods, oily foods, outside junk foods, sweets and sugars as much as possible. Ask him to have 4-5 short meals per day, instead of three big meals. drink plenty of water in between meals and little water during meals. He can take pantoprazole 40mg once in the morning half hour before breakfast for one week. Sometimes stress can also trigger gastritis. So try relaxation methods like yoga or meditation. Also do not starve for too long. If this doesn't give him relief then he should consult a general surgeon for further evaluation.