Mike Mason has to be a Haemorrhoid as he's the worst possible pain in the backside.
The good news is effective treatments are at hand, for instant relief his LandLady/Goddess just sends him to work away for 4 days. She grins and bears the painful discomfort for the other 3 safe in the knowledge he's paying for all her horses sugar lumps.
Dirty Peter is surely The Appendix. It dosen't serve any real purpose but can become very nasty if it becomes inflamed.
It's removal is highly recommended.