What Is A Permanent Solution For My Toddler S Chronic Constipation, As He Depends On Muout Daily?

My son is two years old. He is suffering from severe constipation problem since he is 8 months old. I consulted many doctors. They gave muout powder. If it is not given per day, next day he is suffering. Please i want the permanent solution. More than 1 year i am giving this powder.