The problem you are describing can be because of some sort of food allergy
, which is giving rise to this problem. If you already have made confirmation that you are not suffering from any infection or IBS
I would suggest you to test and try with different food which suits you most and try to stick to that type of food articles only. It is there that some time some people are not ok with all the foods.
I would also suggest you to take the help of some nutritionists to help you to find the perfect diet plan
If you are suffering from some sort of food allergy than only way to treat is by avoiding that food.
Thanks and take care.