Hi doctor, my 17 year old cousin has been struggling to relieve himself after eating since early 2019 and has been going to the public clinic for help but has not received any meaningful diagnosis or treatment. what could be the cause?

Constipation?: Each person with constipation needs to be sure there is no other disease causing it. If constipation is just due to slow movement of the food and poop through the gut, then the things to try are vegetables, water, prune juice, prunes, fiber-with-water, polyethylene glycol, Senokot or other senna, milk of magnesia, other laxatives... A doctor can evaluate and maybe prescribe helpful medicines too.