How funny about the wet feet & litter & I can relate to my cats dipping their paws in water & then going to the litter box..
Ok I have raised cats all my life & have six indoor ones now.. I do not think you have a digestive problem.. However it is always best to have your baby get checkups from the Vets.. Now he is at the age to do the hopping out of the litter box premature.. I think it is a oh I forgot to wipe issue & or someone or something has distracted his consentration.. Also if you have a litter box to close to house traffic & or too close to food/water bowls they will do that.. It seems to make cats nervous & want to leave quickly.. Hope this helps.. Now we need pictures of your baby Melvin..