You need to take things slow, try using small toys or fingers first and should do this for a couple of weeks. If you don't want a bad experience you should do it right. You'll have to gradually build up to actual penetration with his penis. It will take time, but you will enjoy it much more. Sometimes bleeding does occur, that is why you should start small and slow. As far as having a BM while your engaging in anal or worried that he will have "poop" on his penis, try not to eat for about 3-6 hours prior to having anal. This helps greatly and won't ruin the mood by have poop him or you. Just remember, start small and slow... You will want it more when you reach your goal, having anal penetration with his penis. Also, look information up on the internet, but do a little research because there are quite a bit of incorrect information and you don't want to get hurt. Use lube and try anal beads, dildos, plugs, there are many things that get prepare you for anal; Try visiting an adult entertainment store and ask the sale person questions, after all they should know a thing or two about the items they are selling.