That bathroom run you make every morning to clear your bowels can actually make you a lot of money. 

A nonprofit organization called OpenBiome, which has only been around since 2013, allows people to make up to $13,000 a year by donating their poop. 

The only catch is that you must be really healthy to be an approved poop donor. 

"It's harder to become a donor than it is to get into MIT," co-founder Mark Smith joked in an interview with Washington Post. (And he would know - he got his PhD in microbiology there!) 

Over the last four years more than 1,000 people expressed interest in becoming a poop donor on his website but only four percent have passed the extensive medical questioning and stool testing, Smith told WP. 

The screening process costs OpenBiome $5,000, so when they actually find a match they hold on tight. To keep the donors coming the nonprofit pays $40 per poop sample, with a $50 bonus if you come in five days a week. That adds up to $250 for a week of donations - or $13,000 a year. 

When OpenBiome collects the sample they freeze the stool, which is then administered to patients who are very sick with infections of a bacteria called Clostridium difficile (C. difficile). 

C. difficile occurs when something upsets the balance of the normally harmless microorganisms in your gut grow out of control and make you sick, according to WebMD. Symptoms of C. difficile include watery diarrhea, up to 15 times each day, severe abdominal pain, loss of appetite, fever, blood or pus in the stool, and weight loss. 

Antibiotics can help treat the disease, but the symptoms usually come back as soon as the antibiotic is stopped. This is where the donated stool samples come in handy. When healthy fecal matter gets into the gut of a patient (usually by endoscopy, nasal tubes, or swallowed capsules) the C. difficile can be abolished for good, reported WP.

"We get most of our donors to come in three or four times a week, which is pretty awesome," Smith told WP. "You're usually helping three or four patients out with each sample, and we keep track of that and let you know." 

Fellow co-founder Carolyn Edelstein told WP that while many of the donors come to them with interest in the money, they enjoy hearing that they helped save patients. 

"They also love to hear us say, 'Look, your poop just helped this lady who's been sick for nine years go to her daughter's graduation,'" said Edelstein.