As a gay man who's been searching for the perfect man ass for over thirty years - I know more than a little about bottoms and their hygiene habits along with what works and what doesn't. First off, medically there is a huge difference between a quick light "rinse" enema where you're putting a few ounces of warm water into your lower colon and emptying it out immediately, and a deep cleansing enema or high colonic irrigation. HUGE difference. Most of the guys I've had over the years kept a show nozzle/douche attachment in their shower. A quick squirt and rinse to empty and they were good to go. While I love fucking a great man ass, I hate the smell of shit and pulling out a condom covered with it is about the biggest turn off I can imagine. I've been known to pull out, see the mess, walk into the bathroom, shower, and leave without saying a word for fear that if I did say anything I'd end up telling someone what kind of an inexperienced pig I thought they were! I realize that an occasional bit of fecal material may come in contact with a condom. I'm not talking about a miniscule bit of it - I'm talking about some guy who was dirty and knew it and yet in his drunken or drugged out state wanted to get fucked so badly he didn't bother to monitor the condition of his own body. That makes me furious when someone does such a thing to me.
On the flip side - a guy who's clean and careful can be a joy to make love with and I can spend many happy hours buried deep inside him banging that prostate until he's begging me to stop and still hoping I won't!
I do have a bit of a problem with smaller guys or asian men who want to have me fuck them and then cannot open large enough to take the circumference I happen to have. I'm about 6.5" around fully erect and it's fairly even from the head to near the base and then it gets about 1/2 inch thicker at the very bottom. I've met several men who in spite of a lot of foreplay and lube just could not get their body to open to take me and we tried for hours. I'm not into rape (unless as a fantasy scene my partner is into as well) so just forcing my way into them has never been appealing to me. I did that to a guy once in my youth when I was inexperienced and really horny and half drunk and ended up taking him to the ER and he had to have surgery to repair a fissure I created. He was not ready and I grabbed his hips and gave one very powerful thrust and forced the entire length of my penis into him in one deep thrust. He screamed and by the time I pulled out he was bleeding dark red blood. (Dark red is not good, lighter red is generally superficial blood vessels that have broke,but the dark red can be arterial or indicative of a serious injury) We tried packing him for a few minutes and the gauze 4x4's were quickly soaked thru and I was afraid he would loose serious amounts of blood, so I took him into the ER. Fortunately the attending in the ER was another gay man I knew and he managed to get the kid calmed down, admitted, and a proctology consult the next day. They dilated him and went in and sutured the tear and it healed in a few weeks. Scared the hell out of me, and I realized that the circumference a few had complained about could really do some damage if I wasn't careful about who I fucked and how I fucked them.
But for you guys who are larger than average - especially in terms of circumference rather than just length - when you're having anal sex with someone who's built small or unable to relax - DO NOT force your way in. You might not be as lucky as I was and actually do some serious damage and not be able to fix it in time...