Author's Notes:

I did this chapter by request. I hope the quality's not too low, this is harder to do than a pee holding contest. (The intro is a little rushed but the quality is in the actual contest)

Also, this is set in the Equestria Girls world.

"Hey, wanna have a holding contest? But with shit instead of pee?"

Rainbow Dash said this to Applejack when all seven of the Equestria Girls were hanging out at the park.

"You're on," said Applejack.

"Oooh, sounds like fun!" said Pinkie Pie. "Count me in!"

"I... I'd like to enter as well." Sunset Shimmer blushed lightly.

"I don't want to take part in such a disgusting and unladylike contest, but... if you're going to, I might as well." Rarity secretly liked getting dirty.

"Well if you two are entering, so will I," said Twilight.

"Well... if the rest of you are doing this contest, then I will too," said Fluttershy quietly.

So, first they each went home and changed into a different outfit than what they were wearing today. Except Rainbow Dash, she stayed in her skintight black shorts under her dark pink miniskirt. Applejack and Sunset wore jeans, Pinkie Pie wore short, tight jean shorts, Fluttershy and Rarity wore short, skintight shorts, respectively green and purple, and Twilight wore her fairly tight purple shorts from Legend of Everfree.

Then, packing their usual dresses with them, they went to Applejack's house where Applejack cooked them a big meal consisting mostly of food that would make them poop, both very badly and very messy.

Once all the girls were stuffed with this food, they went to Rainbow Dash's house, where they could have their contest in Rainbow's backyard. Rainbow Dash could change here if she lost, but she was sure she was going to win.

"Here are the rules," said Rainbow Dash. "If you mess yourself all the way, you lose. Spike will make sure none of you try to pretend we didn't."

"That goes double for you," said Applejack.

"So," Rainbow continued, "if you lose, you must sit down in your mess for the rest of the contest. If you have to pee, or poop again, either hold it or just do it right there."

"Ugh," said Rarity, who acted disgusted but could barely contain her excitement.

"So... begin!"

Half an hour went by, and they felt nothing.

Then, Rainbow Dash lifted her leg and farted loudly.

PPPPPPPRRRRRRRT!

Pinkie Pie giggled and let out a loud fart of her own.

PPPPPPFFFFFFFFFT!

Sunset's stomach growled. "I think I'm starting to feel-" BBBBBBBRRRRRRAAAAAP!

"Nice one, Sunset," said Rainbow, slapping Sunset's butt lightly. Sunset blushed and giggled.

"Urgh..." said Twilight, who let out a loud wet fart immediately after. PPPPPFFFFFRRRRT!

"Applejack," said Rarity. "Are you sure the beans were there for..." FFFFFFFRRRRRRRRRRT! She blushed.

Fluttershy tried to fart silently, but ended up farting as loud as the others. BBBBBBBRRRRRRRRRRRT! She blushed beet red.

"Let's make this a farting contest while we wait!" said Rainbow, and she let out another boisterous fart that lasted 9 seconds.

Pinkie Pie farted just as loud, but more high-pitched, for 7 seconds.

"Let's just remember the contest we're actually doin'," said Applejack, farting loudly as soon as she said this.

They farted for another half hour. Although they were outside, it was starting to smell really bad. Around this time Fluttershy was feeling less embarrassed, and was giggling a bit at her own flatulence and everyone else's.

"I feel another big one coming on!" said Pinkie. "Try to top this!"

PPPPPPPBBBBBBBBLLLLLTTTTTTHH!

Pinkie blushed. "I think I farted a little too hard..."

Spike looked at Pinkie's butt. There was a big bulge in her jean shorts, which were now brown at the back.

"Pinkie-"

"I lose!" said Pinkie, who felt the big mess in her shorts consisting of a lot of small but wet particles. She sat down, and giggled at the feeling of the mess squishing under her rear.

"I told you not to make it a fartin' contest," said Applejack.

"Even if it wasn't that probably would have happened anyway," said Pinkie cheerfully. "I love farting so much, and this isn't the first time I've had an accident from farting too hard!"

As the minutes went by, the six remaining girls continued to fart, but none of them messed themselves for a while.

Twilight groaned about 40 minutes in. "This next one feels-"

PPPPPBBBBLLLLRRRRT!

Twilight felt her butt. Her underwear felt a bit wet, but there was no mess, so she sighed in relief. Spike checked just to make sure.

Rarity let out an even louder wet fart.

"Unnnnhhhh..." moaned Applejack, and she could feel the logs of poop slowly making their way out of her and into jeans. She tried as hard as she could to stop it, but it kept coming out. She couldn't believe she had lost so early in. But then, she had eaten a big breakfast today.

Once Applejack finished she sat down, finding the sensation to be weird, but she didn't mind too much.

20 minutes later, the five remaining girls' farts started to get wetter and smellier, and they could feel the pressure in their bowels.

Rarity let out a loud, wet fart that stained the back of her shorts, but she was still in the contest.

Rainbow Dash farted even louder, and she was sure her shorts were as dirty as Rarity's, but with no mess in them she was still in. "Oh no... I really gotta pee too! I shouldn't have drank all that cider..."

Fluttershy released a loud, VERY wet fart, and blushed.

Twilight and Sunset let out a series of boisterous wet farts, which made their underwear dirty but didn't mess them.

Pinkie Pie peed in her already-soiled shorts.

Fluttershy moaned as two more farts made their way out of her, each wetter than the last, and then she couldn't hold it anymore. She blushed beet red as she noisily released a wet, brown mess similar to Pinkie's into her skintight shorts. Not wanting Spike to make a big fuss, she sat down, thankful that none of the other girls commented on her accident.

Twilight's farts were the wettest of the bunch and the pressure in her bowels got so intense she suspected it was diarrhea. She was sweating profusely with the effort of holding it in.

And, after a few more wet farts, she lost control and made a mudslide in her shorts. Some of the diarrhea ran down her back legs. Spike didn't even have to say anything because it was obvious to the other three girls that Twilight had soiled herself. She blushed lightly and sat down. It wasn't as squishy as the others, but still felt a little weird, and fun in a naughty sort of way.

"Two more down," said Rainbow Dash, for only she, Sunset, and Rarity remained.

All three of them farted loud and wet every few minutes, getting their underwear even dirtier. Rarity and Sunset had brown stains on the back of their pants, and Rainbow was sure she was just as dirty as them.

Although the farts got wetter, the pressure in their bowels became more intense, and they weren't sure how much longer they could hold it.

They held it for another half hour, after which Rainbow Dash needed to pee as badly as she needed to poop, so she decided to ease the pressure by peeing herself. She was careful to release only the contents of her bladder and not her bowels, and since this was a scat holding contest, it didn't count as her losing. Due to the intense pressure in her bowels and the effort of holding it in, she did not sigh in relief as she soaked her shorts. She nearly lost it near the end and stopped peeing. She was sure her bladder wasn't empty, but at least most of the pressure there was gone.

Another half hour went by, and Rainbow Dash, Sunset, and Rarity continued to hold it in. Their underwear and shorts/jeans were dirty, smelly, and, in Rainbow's case, wet, but they still were able to avoid a full blown accident.

During this half hour, Pinkie Pie farted a few more times, and messed herself again, giggling as though she enjoyed it. She, Applejack, Fluttershy, and Twilight smelled REALLY bad, as they were still sitting in their soiled shorts/jeans.

"Let's make things a little more challenging," said Rainbow Dash. "Let's all squat down as though we were taking a dump in the woods. Of course, don't pull your pants down or you'll be disqualified! After 30 seconds you can stand up again."

Rainbow, Sunset, and Rarity squatted down.

PPPPPPPPPPPBBBBBBBBLLLLLLLLLLTTTT!

Rarity blushed as, five seconds in, a very wet, brown mess loudly made its way out of her butt and into her shorts. Realizing she had lost, she stood up. So much had come out that some of it started to leak through the leg holes and run down her legs. She giggled nervously, and sat down, secretly enjoying the feeling of her mess squishing under her rear, while making a disgusted face.

Rainbow and Sunset let out a few boisterous wet farts, but they managed to hold everything else in for the 30 seconds, and stood up.

More time went by, and Rainbow and Sunset fidgeted hard, feeling like they were about to lose it any minute now, farting louder and wetter than before.

25 minutes went by. Sunset let out a loud, wet fart for 8 seconds that made her jeans even dirtier, but she was still in the contest, as there was no real mess in her pants yet.

Rainbow Dash lifted her leg.

BBBBBBBBBBRRRRRRRAAAAAAAAAAP!

She chuckled as she let out a boisterous deep-pitched fart that lasted 12 seconds.

Spike checked Rainbow Dash's butt. It was hard to tell with her shorts black and under her skirt, so, reluctantly, he put his front paws on her butt. Rainbow didn't mind, for she was the one who told Spike to make sure no one cheated. Her butt felt very wet, but there was no mess between it and her shorts, so she was still in the contest.

They held it for another 25 minutes, during which Fluttershy, Applejack, Rarity, and Twilight, in order, peed themselves. As Twilight peed, she also released the second wave of diarrhea into her shorts.

Sunset needed to pee now too, so she fidgeted even harder. She was afraid to do what Rainbow Dash had done, for it might make her lose control of her bowels as well.

Rainbow Dash was having a really hard time now. She tried her hardest to hold it in, farting louder and wetter every few seconds.

Sunset let out a particularly boisterous fart that made her pants even dirtier, though she still didn't fully mess herself yet. She wasn't sure how much longer she could hold it.

And then...

PPPPPPPBBBBBBBBLLLLLLLLLLLLSSSSSSSSSSSH!

Rainbow Dash froze as she made a very noisy, very wet mess in her shorts. Like Rarity, a lot came out at once and began to run down her legs. She blushed lightly, but sighed in relief, and sat down, enjoying the squishy feeling against her rear.

"I can't believe I lost..." said Rainbow Dash. "Well Sunset, you win! I'll sit here until you relieve yourself however you want."

Sunset couldn't believe she had won this contest. She didn't think she could hold it longer than Rainbow Dash.

She started to walk toward the house to go to the bathroom, when suddenly, she farted one more time, and felt the big mess come out just as fast as Rainbow Dash, heavily soiling her jeans, although a lot quieter than Rainbow Dash and Rarity. About a second into her accident she started to push it out faster, knowing it was lost and feeling little shame, as all the others had done the same. She also started peeing, enjoying the relief as well as taking a bit of naughty pleasure in it.

Once Sunset finished wetting herself and soiling herself, she sat down with the others and felt her mess squish under her butt. She liked the feeling of it.

All seven of the Equestria Girls were wet, dirty, and smelled really bad. But, they laughed it off, walked into Rainbow Dash's house, and took a big long shower together (Rainbow Dash had a shower big enough for seven people), still wearing their soiled outfits and washing the poop down the drain, after which they threw their outfits, which were still stained and a bit smelly, in a laundry basket and finished their shower with soap. Once they were clean, they changed back into their original outfits, Rainbow Dash putting on her jeans from Legend of Everfree.

Afterwards, Rainbow put their wet, soiled outfits in the laundry and used her most powerful detergent, and when they came out of the dryer, no one could tell that the girls had messed them. Except for Pinkie's light blue panties, which had a small brown stain on them from Pinkie soiling herself twice and sitting in it for so long, but her shorts and the other girls' panties were completely clean.