Hi
This is a case of Chronic Constipation. Also considering his age, to give any kind of diet advice I need to know more details (Latest reports, case history of any co-morbidity [If present], Current Diet Pattern etc)
Next Steps
You can consult me if you are in Delhi or any Qualified Dietitian for the same with all the details (Graduate +Post Graduate in Nutrition from recognized institution)
God bless!