i know this is off topic but i could do with some advice. my flatmate has personal hygiene problems. he doesn't wipe his arse, i know this because his soiled boxers are littered across the floor of his bedroom and around the washing machine. if you enter his room, your eyes will water with the stench.

his putrid odour used to be confined to his room, but this last couple of weeks its got worse. if he is to stand next to you, you can smell it. furthermore, when he sits on a particular seat for more than a couple of minutes, he leaves his foul scent behind. both couches in the living room now stink because of him. it has become unbearable.

i've never thought i'd have to tell a 20 year old lad to wipe his bum properly, so i don't know what to say...
any suggestions?