Thanks for contacting healthcare magic.
Your son has problem of severe
constipation problem that one may be because of lack of fiber and water intake in diet.
Intestinal obstruction also cause severe constipation problem. Lack of bowel movement may cause constipation.
Take more water per day..
Eat fresh fruits like kiwi ,avocado, peach ,Orange and green vegetables.
Avoid too much fatty foods and junk foods.
Properly chew a food.
Avoid gaseous foods like cabbage, cauliflower, carbonated drinks, turnips...etc.
After taking this much care still symptoms are present than consent a gastroenterologist for further treatment.
I hope my guidance helpful to you..
Take care.
Thank you.