Matthew felt something wet smush into his pants and immediately knew what was about to happen. He clamped a hand to his ass and made a beeline for the nearest bathroom. While Matthew was running to the bathroom, a few wet sharts managed to squeeze their way out of his clenched asscheeks.
Plluurrfftt! Plluurrfftt! Plleeeaarrfffsshh! Dammit, I'm about to shit on myself! Matthew thought and hurried into the bathroom. He quickly unbuckled his belt, snatched his pants down, and slammed his ass down on the toilet seat.
Not a second later, a loud groan was forced out of him as multiple waves of diarrhea sprayed out of his ass.
"Oh God," he sighed and gripped the rail next to him while his ass erupted into the toilet.
SSHHHHLLLLEEEAARRRPPPHHH! PLLLLOOUUUURRGGGHHH! FLLLARRRGGGHHHHH!
This went on for roughly 5 minutes. Afterwards, another wave of lumpy diarrhea followed.
SSSSSHHHHLLLLLLEEAAAARGLRGLRGLRGLRGLRGLRGLRGLRGLRG!
After that, multiple solid lumps followed, squeezing out of his ass and plopping into the toilet, followed by even more diarrhea.
Plop! Plop! Plop! Plop! Plop! Shhhhllleeeaaarrrr!
After a few more minutes, he grabbed the toilet paper, wiped himself, flushed the toilet, washed his hands and exited the bathroom.

-After Lunch-

Matthew was now in his room, working on his laptop when he felt another strong wave of cramps in his stomach.
Pllleeaaarrfffttt!
"Oh boy, here we go again," he sighed as he stood up and hurried off to the bathroom.
Once in the bathroom, he hurried over to the toilet, unbuckled his belt, snatched his pants down and sat down on the toilet, just in time for a wave of diarrhea to come spraying out of his ass.
He groaned from the sheer speed that it shot out of him at, burning his anus as it erupted from his ass into the toilet.
Pllleargpleeaargghplloouurrgh!
Ppllllaaarrfffttt! Plffaarrffttt! Pllleeaarrrfftt!
Matthew was clutching his roiling stomach as he continued to explosively shit on the toilet.
SHHHHLLLEEEAAARRGGGHH! PPLLLEEAAAARRGGGHHHH! FFLLLAAARRUUUUGHHHH! PPLAAARRFFFTTTTTT!
"Dammit, what the hell is wrong with me? Did I eat something?" He wondered before another violent diarrhea wave exploded out of his ass and splattered the toilet bowl.
PPHHHLLLEEEAAAARRRRRGGGHHHH!
"Ngh!" he groaned, clutching his stomach with one hand, and the rail beside the toilet with the other.
He waited a few more minutes, and nothing else happened, so Matthew grabbed the toilet paper, thoroughly wiped himself, washed his hands, flushed the toilet, and once again exited the bathroom.

-After Dinner-

Now this time, Matthew was in for a really rough time because he had mistakenly eaten something that he knew his stomach couldn't handle.
He was just about to clean up, until he felt a really strong cramping in his lower gut and then a loud and greasy fart slipped out of him.
Flleeaarrfffttt!
Oh no he thought, and then realized.
Oh shit, I forgot that my stomach can't handle seafood.
Not a second after he thought that, a shart squelched into the back of his pants, forcing him to clamp a hand to his ass and dash towards the bathroom.
When Matthew finally made it to the bathroom, there was a brown smudge showing through the back of his pants. He hurried over to the toilet after locking the door, unbuckling his belt, snatching his pants down, and sat down on the toilet.
As soon as he sat down, a wave of diarrhea sprayed out of his ass so violently, he thought he was shitting lava. He squeezed his eyes shut and grit his teeth, clutching his cramping stomach while his ass very violently erupted into the bowl.
SHHHHLLLLAAAARRRGGGGGGHHHH!
PPPPLLLLLLAAAAAARRRRRGGGGHH!
FFFFFFLLLLLLLEEEEAAAAARRRFFF!
SSSSHHHHHHLLLLOOOUUURRRGGG!
SSSSHHHHHHLLLLLLEEUUUUURRRFFF!
"Gugh!" He groaned from the fiery pain down in his asshole that was being assulted by the constant eruption of liquid diarrhea. After about 2 to 3 minutes, the wave of diarrhea finally stopped.
He leaned back against the toilet seat and sighed with relief.
"Note to self, be very careful when you're around seafood." He said to himself. After resting for a few minutes, he gently wiped himself, washed his hands, flushed the toilet, and left the bathroom.