Just before Pinkie Pie’s rectal exam was about to begin. Pagan discovered a flaw in the magic shield. That would cause it to fail during the exam. He started rapidly tapping on the sound proof shield. Trying to alert the problem to the nurse. Unfortunately for the little stallion it was misinterpreted. As his impatience to start the exam. Pinkie not wanting to make him wait any longer. She proceeds to come up behind Pagan. Turns around and sit upon the magic sphere. Pushing the sphere up into her ponut. The pink muscular ring easily engulfed it. By reflex the mare’s anal muscles contracted. The pink earth pony letting out a soft moan. As she felt it get swallowed down her anal canal and into her rectum. Following the nurse’s instructions pinkie stands up. Then gets into the downward dog position. Wiggling her flank in the air and flexing her anal muscles. To work the sphere deeper into herself. So Pagan could examine deep into her bowels.
 
Inside the sphere Pagan is in a state of panic. Unable to stop himself from descending deeper into the earth pony’s bowels. As cracks are quickly spreading across the surface of the shield.
 
Back outside Pinkie Pie feels the sphere. Slide down her rectum and disappear into the depths of her colon. The pink mare stands up on her hooves. With a very intents blush on her cheeks. “Um nurse think I may have pushed him a wee too deep.”
 
An hour later after many failed attempts to push the stallion back out. The nurse lets out a exacerbated sigh. “It seems that he has gotten stuck again. I have to reschedule all his appointments now.” Pinkies looks at the nurse in surprise. “This has happened before?” “Yes but thankfully it is rare. Most ponies can’t work him that deep. But every once in a while one manages to. Get him stuck deep in their colon. Not to worry he will eventually be pushed out. By your next bowel movement.” Pinkie pie’s muzzle scrunched up in disgust. “Yuck he will be all covered in my poo.” The nurse stops herself from face hoofing. “That is what the magic shield is for. Your poo will never touch him. Just bring him back up here when he is out. We will have a lot of exams to catch up on.” With all her worry put to rest. The Pink pony left the room excitedly bouncing.
 
Inside her the magic shield gives out. Leaving the stallion to be thrown about her colon. Bouncing off the slimy waste coated walls. An Pagan’s crappy day is just getting started.

@PerryPony  
That’s more or less what he’d be.

@SinnerWhoKeepsTrying1978  
There’s probes.

I can see this as part of a story in which Pinkie approaches her doctor with some sort of digestive issue she’s been having. Naturally, wanting to know more about it, the doctor, a unicorn, shrinks himself down and forms a protective bubble around him. Then, just as he’s right under Pinkie’s anus, he starts to wonder if he’s going about it the right way. But, it’s too late, and Pinkie’s starting him on his tour of her digestive system, but in reverse.

Well that’s the kind of vore I could maybe possibly at some point get into?  
Just being inside a translucent sex toy.