Poor you! I suffer from these too. I don't know how to prevent them but the only thing that clears them is Betnovate cream. After just 2 applications, they clear. Magic! The cream doesn't stay active long after opening the tube though, so you'll need to get repeat prescriptions as and when needed. My doctor suggested using just water to wash the area. Easy in the shower: let the water run down that area for a long time. He also said that excessive rubbing with toilet tissue makes it worse (not always easy to avoid using it!) He said dabbing damp cotton wool after defecating is best. Mind you, I think that would probably block the drains! Not easy, is it! Hope you find a solution!