Whats wrong with my Guinea Pig?

My guinea pigs nose has been letting of discharge and his bum was blocked but i assisted him in getting rid of all the droppings .. hes a male guinea pig. Hes not running about his cage as much and hasnt been eating as much .. hes been like this for a few days and im taking him to the vet but i cant take him untill monday as the vets arent open over the weekend. Any ideas on what this is and how i could help untill i get him to the vet? please help.