Originally Posted by minmin12
My suggestion to you would be put food and water near litterbox for a while.
Totally disagree with this advice, and don't understand the rationale behind it. Cats don't like to have their eating station near their bathroom, and putting them close together could make the problem worse.
Has your cat had a check-up recently? Could there be a medical reason for his litter box avoidance? Young male cats eating dry food (what does he eat, by the way) are terribly prone to urinary tract issues, which can also be influenced by stress. A urinalysis might be a good place to start.
Beyond that, I would suggest picking up some Feliway diffusers (they emit calming pheromones and could help with whatever stress your boy is experiencing). Perhaps adding a couple more litter boxes, and making sure you scoop them at least twice a day, would help. Is the box you have now covered? If so, get an open one or take the top off. If it isn't covered, maybe give him the option of one that is (but keep the other one as well).