I have been noticing a problem with my guinea pig.?

I have a 2 year old male guinea pig. Over the past few weeks I have been noticing an unusual problem with him. When I picked him up today to move him to his smaller cage while I cleaned out his big one I noticed a clear, semi solid substance in his penis. It was lumpy and about the size of a pencil eraser. I know it must have hurt him. I got a q tip an slowly nudged it out. It was semi solid, almost like a super thick jelly and was lumpy. I am worried and unsure what it was. I don't want him to get sick, he is my little baby, and I have taken care of him the best I know how to since he was a tiny little baby. Has anybody else has something similar happen to their guinea pig?