I could be a lot of things. You mentioned garbage and dirty laundry.... Two things bullies love to snack on. He may have eaten either some garbage or an article of clothing that has given him an upset tummy. Eating and drinking are good signs. If he gets to where he won't eat or drink or has nothing but explosive runny poo then get him to the vet for a possible obstruction. if he did eat something depending on what it is he will either puke it up or pass it in his poo. My Harlea loves to eat socks. The first one she ate she puked up the same day and teh second one she didn't puke up for almost 2 weeks.