Before getting into shorts/bibs prep with a good cleansing using baby wipes. They can be had for cheap at the big discount stores in bulk and can be easily carried in a small ziplock sandwich bag for use during the ride (for post bathroom cleanups/ rest stop fueling cleanups/postcrash cleanups and the baggie keeps them from drying out. I have young kids, so we keep these in the vehicles for easy on the road cleanups (all sorts of spills and mishaps happen) and I started using them for pre rides after seeing what they do for diaper rashes. As for getting rid of, keep the skin surface clean and dry and don't wear tight fitting undergarments to irritate the sore, Treat the area with either diaper rash ointment of with a hemmorhoid treatment (such as Tuck's medicated pads or Preparation H).