This seems to be problem in your digestion capacity. Considering your age this seems to be problem because of food habits and timings. Next time you eat mutton have some pinch of dry ginger powde with pinch of corromder powder it will help to digest
Next Steps
Consult on Practo platform for further Counselling and in detail treatment options
Health Tips
Eat only when your hungry enough,let it be mutton or any food.