This could be in the same universe as "In The Closet". It's probably not going anywhere, though.
The first time Wilson tried to help House with his ... bathroom problem, House fought back. He couldn't help it, something he tried to explain to Wilson, but he just couldn't lie still and let Wilson... do that to him. And tying House up wasn't an option, because House would need to move about, and he was too big for Wilson to move him if House was in strict bondage.
The next time, House didn't tell Wilson he was having a problem, but Wilson figured it out anyway. Instead of tying House up or beating House into submission, he collared him.
Wilson had never put a collar on House before. He slipped the smooth cool leather around House's neck, and buckled it close, sliding his fingers into the D-rings and tugging. House felt the tug and went down, his mouth opening in wonder. He had never knelt for Wilson so easily. Wilson held up a metal tag, a dog's tag not a military one, with Wilson's name and address and phone number on it. "Shall I tag you as well as collar you, House?"
House let out a small, agreeing whine. Wilson laughed at him, petting him. "If you're a good boy, now. Come on. Are you going to be a good boy?"
House had dropped his cane when he knelt. He hadn't handed it to Wilson, as their scenes usually began, surrendering his power of independent movement to Wilson, he had just dropped it. He realized this when Wilson tugged him to his feet, his hand under House's arm, and began to walk House towards the bathroom. House knew what was going to happen when they got there, he was afraid of it and he was afraid of fighting Wilson, but the light firm touch of the collar on his throat seemed to encompass his world.
Wilson stripped him. House was pushed down on to his back on the bathroom floor, and Wilson knelt down beside him, rolling up his sleeves. "You won't have to hold this first one more than five minutes, House." House watched, his mind seeming to work slowly, as Wilson filled the enema bag and hung it on a stand before kneeling down beside him and snapping on gloves. The latex felt cold against his anus, not warm, or perhaps that was the KY jelly Wilson was pushing into him. Wilson screwed an enema nozzle on to the tube, and slid it into House.
House lay still. He could see the bag deflating and feel the warm water flowing into him. Stuffed and helpless on the nozzle Wilson held inside him, he whined in desperation, shivering. Wilson's hand moved on his belly, his face fascinated. House felt a strong cramp hit him, and squirmed on the floor, pressing up against Wilson's hand.
"Hold it, House. Hold it." Wilson spoke softly, his voice fascinated. "I didn't put much in this time, you can hold it for a little bit more. I know you can. Be a good boy, now."
The awful pressure passed. House pawed at Wilson's arm. Wilson seemed to understand, and helped him up, over to the toilet, and stood holding him, his fingers enlaced in the collar's rings, letting House push his face into Wilson's belly, as House's colon let go of the water.
"Good boy," Wilson said. "That feels good, doesn't it?" He petted House, and made him get up again. This time he positioned him over the bathtub, his chest resting on the edge of the tub, head down: almost like being on hands and knees for Wilson, but with more support for his leg. He showed House the enema nozzle, even larger than the previous one, and lubricated it with KY. "This time I'm going to use two quarts."
If not for the collar, House would have fought. But he felt the warm grasp of it round his neck, as if Wilson had taken his throat in both his hands and squeezed just enough to let House know he was there. The fat nozzle slid into him coldly, not like Wilson's cock, and the warm liquid began to flow out of it, into House, slowly filling him. He opened his mouth and no words came out, only a mewl of helplessness. Wilson owned him. Wilson was filling him up and would empty him out.
House felt Wilson's hand on his swollen belly, stroking and gently prodding. He whined, feeling a cramp rolling through him. "Hold it," Wilson said softly, like a lifeline. "Hold it. Good boy."
House was crying. Not loudly: tears were just rolling out of his wide-open eyes and landing in the tub. "Good boy," Wilson crooned, petting his belly. "Hold it, good boy, just a minute more, oh you're such a good boy..."
He pulled House up and walked him the two steps to the toilet. House sobbed painlessly and let go, the water rushing out of him, filth pulled loose, Wilson holding him.
"I wonder how many quarts you can hold?" Wilson said out loud. "They say seven, for an adult male. Do you think you could hold four quarts this time, for me?"
It wasn't really a question. Wilson was just talking out loud. He positioned House over the edge of the tub again, and again the flow of warm water filled him, and filled him, and filled him. He hadn't really stopped crying, and he was squirming, afraid to move, afraid to shiver in case he had an accident and Wilson punished him for being dirty in the house, he was Wilson's good boy, he could feel his whole abdomen swollen and Wilson's hands kneading him, gently handling him, Wilson murmuring over and over again that he was a good boy, hold it, good boy.
In some interval between cramps House was allowed to sit and release this flood of liquid. He sat still, pushing and rubbing his face against Wilson's stomach, his hands helpless by his sides. Wilson got him to stand up and bend over and Wilson wiped his backside clean, and he sobbed with relief, because that meant no more fillings and emptyings, no more, not now, he was a good boy...
Wilson clipped the tag on his collar, and hooked a finger through one of the D-rings. Stumbling, House leaned on him all the way back down the hall to his bedroom. Wilson made him lie down on the bed.
"You wait there," Wilson said, and House whined softly to tell House he'd heard.
Left alone, he didn't move or want to: he was collared and tagged, he was Wilson's, and he was Wilson's good boy. He couldn't stop crying, but Wilson didn't seem to mind.
"God, the power of seven quarts of warm soapy water," Wilson said. "I usually have to get a cramp in my left arm from beating you to get you like this." He had stuffed KY jelly up House's ass and was positioning himself to fuck him. He was smiling, he looked happy. House whined, shifting his legs to give Wilson better acccess. Wilson grinned at him. "Good boy."
Greg had a dog. The dog was a mutt. Once the dog had learned not to make a mess inside the house, Greg's daddy never punished the dog. Greg had to learn. Daddy had to teach him. The ice-cold enemas made Greg's belly cramp up but daddy insisted Greg had to learn how to be regular. If he messed up he had to sit in an ice-cold bath. If he really messed up he had to sleep outside. The dog would whine and paw at the door to be let out, the nights Greg slept outside. Greg never named the dog. He already knew, when you name what you love, it hurts more when you lose it.