hold him and run ur finger tip along his belly. u shouldnt feel any bumps or anything irregular. it should all squish in and be soft. if u notice a lump from his belly to his vent then that is prolly his poop. if he has a blockage it will be like a lump stuck somewhere. try giving him a warm bath and if nothing then let him crawl around on the floor, that will help move things along. but i wouldnt be too worried just yet