The receptionist led Helen into the classroom. As before, there were a dozen young men in the front row. Helen’s husband was in full professor mode, talking to the class. Helen waited silently until he addressed her.

“Thank you for volunteering today. Your time here is greatly appreciated.” He motioned her to the middle of the room. “In today's class we will be demonstrating the colonoscopy procedure.”

Helen’s heart sank. That sounded like the worst possible topic for a medical lab class that she could think of.

“Normally the patient is required to engage in a liquid preparation for 24hrs prior to the procedure to ensure the lower intestinal tract is empty.” He explained to the class. “But since time with the lab patient is limited we will instead perform a directed bowel cleanse using a hydro flushing colonic technique. It will take about 30 minutes for the cleanse, and then 30 minutes for the colonoscopy demonstration.”

Helen’s brow was furrowed with apprehension. Her husband had not given her any clue about what to expect at todays class. She was beginning to think he liked surprising her this way.

“My assistant will oversee the cleansing.” The professor gestured towards a young man in a white coat standing near the door.

The assistant opened the door and waited for Helen to follow him. He was an attractive young man. Helen admired his broad shoulders and firm buttocks as he led her down the hall and into a room with a variety of unusual machines. He closed the door behind them and guided her to a large device in the corner.

“You can change into this gown, open in the back, please.” He instructed.

There was nowhere private for Helen to change, so she turned her back to him while she disrobed. She was grateful to get a gown this time, and happy to see it was properly sized.

The young man busied himself retrieving various supplies from cabinets. He returned to the machine and helped Helen up onto it and into position. She sat on one cushion and reclined back at an angle. He adjusted the other pads and arm rests until Helen was properly supported. Helen put her feet onto the foot rests, and tucked the front of her gown down between her legs to maintain a bit of privacy. It reminded her of those reclining bicycles with the pedals out in front. It was almost comfortable, but the large stainless steel drain basin below her reminded her this was going to get awkward.

The young man pulled on long rubber gloves up over his scrub sleeves. He fitted a full sized clear face shield and sat down on a very short rolling stool in front of her. She looked between her knees down at him, dreading what he was going to do next.

“I will explain each step as we go.” The young man said. “The only thing for you to do is try to relax.”

Helen took a deep breath, and braced herself mentally for whatever this was going to be.

The young man had a soothing voice, and the way he narrated the process helped Helen relax a little bit.

He turned on an exhaust fan, and then pressed a button on the machine. It came to life with the sound of motors, and the seat cushion separated into left and right halves. They split apart just a couple inches and pivoted slightly outward. This pulled Helen’s buttcheeks apart, exposing her anus to the bare air, and to his inspection. The foot rests also moved up and outward. Helen could feel the front of her gown lifting and pulling taught over the tops of her spread thighs. What little coverage she had was now gone. The man had a full view of Helen’s tenders. She was at least thankful that he was the only person here to see her like this instead of the whole class. He applied a generous dollop of lube to his gloved finger and brought it to her anus. Helen’s muscles were tense, and she felt his slippery finger tip pass back and forth over her tight sphincter. He was gentle, and continued the narration as he worked. To Helen’s surprise she felt her muscles relaxing, and his finger tip dipping into her pucker a little bit on each pass. After a minute or so he was able to gently slide his finger in through her sphincter, and work the lubricant all around the inside of her anus. Helen appreciated his slow technique. It was almost a loving act of foreplay, but once his finger was inside she began to worry about what he might encounter in there.

The young man withdrew his finger and replaced it with a lubricated nozzle. The hose was connected to a faucet with a digital display reading 36 degrees C.

“We’re going to start with a few small rinses.” The young man explained as he turned on the water. Helen felt an uneasy pressure begin to grow inside.

“The first release is the most difficult.” He explained. “I’ll give you a little extra on this first one just to help you push it all out.”

Release? Push it out? Right here in front of you? Helen gripped the arm rests and closed her eyes. She couldn’t bear to watch him knowing he was waiting for her anus release its contents.

Helen tried her best to hold it all in, but eventually her bowels signaled an emergency and made their own decision. The internal pressure exceeded the strength of the seal, and the contents came rushing out of her. Helen groaned to herself in complete humiliation. It was an event she had never wanted to experience, especially with a nice young man sitting before her with a front row view of it all.

The young man didn’t flinch, but instead was quick to insert the nozzle again and resume the flow of more water. This process was repeated three more times, and just as he had predicted it became a bit easier each time. Helen also noticed the expulsions were becoming less sporadic, and more a continuous smooth stream of water.

The young man set aside the nozzle, and picked up a stainless steel device. He inserted the thin end into her anus, squeezed the handle, gently pried her open, locking it just below the point of pain. Helen felt certain she was being turned inside out. The device stretched her sphincter outward in all directions, leaving a clear open passageway to her insides. She froze, anchored in place by this horrid device.

Next the young man pulled the tip of a long silicone tube from a tray of lubricant. He inserted the first few inches into Helen through the wide open portal he had created. He turned another valve, and water began flowing slowly through the long tube. All Helen could feel was the water flowing out of her gaping hole and the sound of it falling to the basin below. He worked it in deeper, slowly feeding the slippery snaking into her bowels.

Helen felt the unusual feeling deep in her belly. It was like nothing she had ever experienced before. It was truly inside her core, pushing from within, and moving around inside her. Helen imagined an alien tentacle, probing her organs, trying to map out the interior pathways of her body.

When the young man felt it was in deep enough he attached an adjustable arm to hold the hose and the anal dilator in place. He explained that for the next 10 minutes it would just be a steady irrigation of the passageway, flushing out all the material and leaving her clean and empty. He adjusted the water flow to a rhythmic pulsing manner, alternating small surges of water with resting low pressure. Then he switched on a motor connected to the foot rests. This moved the foot rests forward and back. When all the way forward, Helen’s legs were almost straight. When all the way back, her bent knees were brought almost to her chest. The young man explained that this motion moved and flexed her colon, helping to work everything loose and completely flush it out.

Helen felt helpless, trapped on this machine, and anchored in such a way that she could not move. The motors repeatedly forced her legs into a squatting position and then extended. There was nothing respectable or dignified about the pose or the process.

The waste water continued to flow out her stretched anus, around the sides of the long tube. Helen was well aware that her body was now part of a water circulation system, flowing in through the long tube, sloshing and squirming around every twist and turn, and then making its way out the only way it could. She was nothing more than an exposed and violated lab rat, being used by a machine.

The young man explained that he was going to do some paperwork in the next room. Helen was to press the help button on the wall if she needed him or if anything felt uncomfortable. Helen nodded silently. She did not feel she could carry on a conversation while being worked over this way.

The attendant left the room and closed the door. Helen took a deep breath and closed her eyes. She felt the water pulsing deep inside her core, creating pressure and then releasing pressure. Then, after the full journey, the flow of water exiting her bottom was a continuous stream pouring down into the basin.

When her knees were pushed up, the squatting position felt exceptionally revealing. With her legs slightly separated she just knew that every hole, crevice, and fold was spread wide open.

Now that she was alone she noticed the knees up position was very much like when she was on her back having sex with her husband. He would sometimes lift her legs or bend her knees back onto her chest. Of course, he was much more gentle than this machine, and usually varied the positions as the mood desired. The machine was putting her through similar motions, but without the enjoyment of actually having sex. She wished she was getting fucked right now instead of being flushed by this awful contraption. As she thought about her husband fucking her, her hand moved to between her legs, feeling the way her labia were spread and stretched on each cycle. She applied a little pressure to her clit, letting the movement of the machine provide just enough back and forth rubbing to the area. There was something nice about the steady repetition of the machine. Once she found the right spot for her fingers to rest, the machine slowly rocked her hand back and forth, slowly building a pleasant glow between her legs.

Helen looked forward to telling her husband later than night about touching herself during the procedure. She would ask him to fuck her in that same position, pushing her knees up against her chest, over and over. Soon, Helen felt the waves of an orgasm washing over her. Her muscles contracting, clenching her pussy open and closed, and squeezing against those tools in her ass. It was a small pleasure in an otherwise awkward situation.

After the waves of orgasm subsided, Helen moved her hand back to the arm rest and steadied her breathing. She wanted to look calm and relaxed when the young man returned. She didn’t want him to suspect she had done anything inappropriate. She didn’t need to add any more embarrassment to the already humiliating situation.

Helen hoped the 10 minutes was almost over and this treatment would end soon. She opened her eyes and looked towards the door hoping for his return. She was shocked to discover him standing right in front of her.

“I’m sorry. I didn’t mean to startle you. You may not have heard me come back in.” He paused, looking at Helen with a sympathetic smile. Helen froze, and tried to shrink back into the cushions. She wanted to disappear. He must have see something, but Helen wasn’t sure of how much.

“I didn’t want to interrupt.” He said.

Now Helen assumed the worst. Not wanting to interrupt meant he saw her doing something, and that something was clearly visible with her legs spread and raised. Helen hoped he would not share this with anyone, especially her husband.

The young man discretely adjusted a bulge in his pants as he sat back down on his stool in front of her. He turned off the foot rest motors and returned her legs to a more typical exam position. He stopped the water pulsing, and then pulled something out of a sterile wrapper. He held up a small sponge ball for Helen to see. He explained that this would travel up through the long tube and be deposited at the top of her colon, where it meets her small intestine. The sponge ball would act as a temporary plug, preventing anything new from entering her colon. It was made of a water soluble material, and once in place it would take about 2 hours to soften and dissolve. It would all pass normally with her next bowel movement, which would probably be later tomorrow.

He opened a hatch at the base of the long hose and inserted the sponge. He closed the hatch and then turned on the water. He watched the bulge in the hose slowly travel along, being pushed by the water behind it. The bulge reached the anal dialator and then disappeared inside of Helen’s body. The man quietly counted to 20, more than enough time for the ball to have traveled the full distance and emerged at the other end. He continued the water flowing as he slowly withdrew the hose.

The sensation of the hose being pulled out was another weird experience for Helen. As he worked, the snaking sensation grew smaller, and got her one step closer to being done.

With the hose removed the man started the foot rests moving again. This was to encourage any remaining water to work its way down and out. Helen returned to the rhythmic squats with little spurts of water coming out. When the young man felt she was empty enough to walk, he carefully closed the dilator and withdrew it from her anus. Helen’s sphincter was relieved to be free of the intrusion, and at long last was able to close itself.

Helen took a deep breath. She had made it though the first half of today’s ordeal. Next she had to go face the class for demonstration. At least she would be back near her husband. Even though they could not acknowledge it, his presence would be very comforting.

The young man dried Helen off and helped her down off the machine. He tied her gown in the back and gave her some disposable slippers to wear. Helen picked up her pile of clothes and followed him out the door and back down the hall to the class.

As Helen walked into the room she felt all the students staring at her. It was a little different than in past times. Maybe it was walking in wearing only a gown, or maybe it was them knowing what the next part of the lesson would involve. Even Helen’s husband had a somewhat surprised look on his face. He guided her to the exam table in the center of the stage, instructed her to lie down on her left side, and to pull her right knee forward.

Helen did as she was instructed, rested her head on a small clinical pillow, and tried to relax. She was thankful that all the students were now behind her and she did not have to look them in the eye as they performed the colonoscopy demonstration. She stared into the distance, waiting for her husband to begin. That is when she noticed a large video screen in the classroom, and the image on the screen was that of a machine just like the one she had come from. In fact, it looked exactly like the one she had been on. Then she saw the young man who had worked with her. He entered into the frame, and proceeded to pack up all the tools and wipe down the cushions. He cleaned everything up, rinsed out the basin, and then walked out of frame.

Helen now realized that her husband and the whole class of students had been watching the whole time, and they had likely seen it all. Everything she had endured was now living in their memory, including the little pleasure she had found for herself when she had thought she was alone. Helen could feel the heat of her face turning a bright red. Tears silently came to her eyes as she waited for her bottom to be invaded again.