Thanks for writing your query.
After reading your post, it seems that you might be having gastritis
Following investigations may be helpful :-
3. Liver Function Test ( LFT ).
4. Serum amylase
5. Stool examination.
I would advise that you should continue with Lansprazole. Further medical management can be planned according to the reports of the investigations.
Following precautions will be helpful :-
1.Avoid spicy and oily foods.
2.Avoid being empty stomach for long periods.
3.Avoid mental and emotional stress.
4.Avoid smoking and alcohol, if any.
5.Avoid self medications, especially pain killers and steroids
6.Drink lots of water daily.
7.Eat light meals prepared under hygienic conditions.
8.Avoid gas producing foods like peas, cabbage, legumes, etc.
I hope this is helpful to you.