Author's Notes:

Just another scat scenario I thought of. Don't read if you don't like shitty stories.

I considered unpublishing this chapter cause I know it'll be disliked except by my usual fans and friends here...

Equestrian magic had come through the portal. But now a different type of Equestrian magic had come through and infected Sunset Shimmer.

It was a sort of magical disease, though nothing serious. An offshoot of the trots, it made ponies have to poop a lot by multiplying what was in their bowels. Due to the abnormal amount of hyperscat, this disease was called Megahyperscat. It was not contagious, and had a cure, but it was only in Equestria.

Sunset did not know this illness existed at the time. The first time she had used the bathroom after getting infected, on Saturday, she had clogged the toilet, and ran out of toilet paper trying to wipe herself. Though the plumber had unclogged the toilet by now, she could not use the toilet until it was gone. So she released the contents of her bowels in her backyard, making a big pile in the corner, and her panties were quickly stained brown when she pulled her pants back up.

On Sunday, she sent a letter to Princess Twilight, who replied, diagnosing her condition as Megahyperscat and saying she'd bring the medicine over in two days.

Because she only needed to go twice or three times a day, she didn't think she needed to stay home from school on Monday. Boy, was this a mistake.

When Sunset woke up, she felt the intense urge to poop. After doing her business outside, adding to her tremendous pile of shit, she showered, had her breakfast, put on a white and pink shirt and a tight pair of jeans, and went to school.

Her first class went smoothly, but on her second class, she needed to poop badly. She knew she couldn't use the bathroom, she'd just clog the toilet. So she held it in, occasionally letting out a dirty fart that would result in laughter from the other students.

When recess came, Sunset was so desperate she decided to go outside. She ran behind the school, looked around to make sure no one was around to see her, and pulled down her jeans and her white panties. She sighed as she made another big mess on the grass under her rear. She hoped this would be it for today, so she pulled her pants back up.

Her butt felt dirty already. She decided to run to the bathroom and wipe it as much as she could. When she got there, all the stalls were full. By the time someone was out, she had just pulled her pants down and wiped once when the bell rang. Sunset sighed and pulled her pants back up.

She sat through her third class in her dirty underwear, hoping it didn't stain her jeans. But at least she was safe from soiling herself.

Until halfway through the class, she felt the intense pressure again. She realized that the intervals between her need to take a dump were getting smaller. She fidgeted, farting occasionally, and did her best to hold it.

"Sunset, do you need to use the bathroom?" said the teacher after Sunset let out a particularly wet fart.

"No thanks, I'm fine," said Sunset, blushing a little.

Once the class was over, it was lunchtime. Sunset ran outside behind the school again, but there were too many people walking around, as some were walking home for lunch, or else eating lunch outside. A few people were examining the pile of shit she had left, which made her blush profusely.

She desperately searched for a private spot to find relief, but there was none, except behind a tree. She ran behind the tree, but to her dismay, a girl and her boyfriend were sitting under it.

So, Sunset returned to the cafeteria, fidgeting as she ate her lunch. She farted a few more times.

"Sunset, darling, why haven't you used the bathroom yet?" said Rarity, fanning the smell away.

"I... I can't."

"Why not, sugarcube?" said Applejack.

"I caught this Equestrian disease called Megahyperscat that makes me poop so much I clog the toilet."

"Then why don't you do it outside?" said Rainbow Dash.

"I tried that, but I couldn't find a spot where no one could see me."

"Did you tell... the other me?" said Twilight.

"Yes, and she said she won't have a cure until tomorrow." She let out another wet fart and moaned.

Soon, it was time for the fourth class of the day. Sunset was more desperate than ever. She squirmed harder, and her farts were getting wetter. She touched her butt and cringed at how wet it felt. She could only imagine how dirty her panties were.

When it was only fifteen minutes left in the class, Sunset accidentally farted again, and felt a bit of poop plop into her underwear. She froze, feeling terrified and embarrassed. She knew she couldn't last much longer, so she raised her hand.

"Yes, Sunset?" said the teacher.

"I need to use the bathroom really bad!" said Sunset.

"I figured," said the teacher. "You shouldn't have held it this long. I'll understand if you're not back in time to finish the class."

Sunset got out of her seat and ran outside as fast as she could. Another sloppy wet fart made its way out of her rear, dirtying her panties further.

As she turned the corner, she saw some workers cleaning up her pile of shit. She heard one of them make a comment as to what sort of horse might be running around here. There was nothing for it but to go behind the tree.

She was halfway there when it happened. With another boisterous fart, hyperscat exploded out of her, filling her jeans so rapidly it started to ooze down her legs. Her panties were overflowed and a bit even leaked out from the top of her jeans.

Once Sunset finished messing herself, she stood still, ashamed beyond belief, but at the same time feeling immense relief. Then she recovered and walked behind the tree, dumping her mess out behind it.

Her pants were still very dirty and she smelled bad. She reluctantly walked to her last class. Some of the other students noticed the state Sunset was in and laughed at her while holding their noses. Sunset had never been more embarrassed in her life.

She sat through the class in her soiled jeans for about twenty minutes before the teacher paused the lesson and took Sunset outside.

"I'm sorry, but we just can't work with this smell. And, I don't think you're up to it right now. You go home early today. I'll tell Principal Celestia you're not feeling well. But, I won't say how, and I'll tell the other students not to speak of it."

Sunset was grateful for this. As she walked home from school, she let out a few more farts, and released another wet mess into her pants before she got back to her house. It wasn't as though her pants could get any messier or smellier.

After taking a bubble bath in her jeans, scrubbing the back of them extra hard with extra soap, she changed into a clean outfit, and she didn't run into any more trouble before she went to bed.

She woke up really needing to poop. And, there was a big thunderstorm outside. Sunset didn't want to go outside into this storm, but she couldn't use the toilet without clogging it. She also needed to pee. Usually peeing into the toilet wasn't an issue, but she was afraid she'd release the contents of her bowels as well.

Sunset held it in as long as she could, farting the entire time and stinking up her room. After about an hour, she ended up soiling her pajamas, and peeing in them. There was nowhere to dump her mess, so she had to stay like this the entire night.

Next morning, after another long bath and shower, and putting her soiled pants and panties in the wash with extra detergent (despite how hard she had scrubbed them in the bath), Twilight gave her the cure. She was still embarrassed to show herself at school, but the other students liked her so much they forgot about it within the week. Despite how embarrassing the situation had been for her, she got over it.