Poopers Guide is an Instagram account providing reviews of private bathrooms that are usually accessible to the public. View Full Caption Instagram/@poopersguide

We've all been there.

You're walking in a new neighborhood, out for a run or protesting for hours in a park when the need for a restroom suddenly hits.

You could hunt for one of New York City's notoriously scarce public conveniences. Or you could turn to an Instagram account with a very graphic name — Poopers Guide.

The brainchild of Williamsburg resident Andrew Maksymowicz, Poopers Guide reviews private bathrooms that are accessible to the public around Manhattan and Brooklyn based on five criteria — cleanliness, comfort, accessibility, size and amenities like Kleenex and changing tables.

"I've been rating bathrooms for 10 years," said Maksymowicz, 31, who works as a manager at a nonprofit organization and who launched his online defecation directory in October.

The water closet connoisseur began his work in written form as a college student frequently traveling from his out-of-state college into the city to reach relatives living on the Upper West Side.

“I always needed a bathroom and never knew where to go," he said.

So Maksymowicz started toting a notepad and camera along to document the best and worst restrooms, particularly in Times Square where he found his need arose most.

He has since expanded the scope of his investigations and enlisted his girlfriend's help.

"She rates the ladies’ room so I have a more fair rating and score," he said.

Like most restaurant critics, Maksymowicz does his inspections undercover. He walks into an establishment off the street and asks permission to use the facilities.

“All these places are more easily accessible if you have the courage to walk into an empty restaurant and just ask to use the bathroom," he said. He acknowledged that factors like race and gender may have an as yet unmeasured impact on the way restaurant staff perceives those making the request.

Maksymowicz gives some of his highest marks to the bathrooms at Felice in the Financial District, the Ace Hotel in the Flatiron District and Juanchi's Burger in Williamsburg.

According to the expert, the Shangri-La of toilets would be stocked with seat covers and a bidet, as well as "fantastic smelling soap, maybe some music playing over speakers, something I can just relax to … and definitely some funky tiles on the floor."

You'll find none of those amenities at the facilities at the Whole Foods in Union Square, so subpar in Maksynowicz's opinion that he recently steered a man and his son waiting in line toward the restrooms at the Burlington Coat Factory nearby.

"I felt like I had done my duty," he said. "What’s the point of having this knowledge if you can’t use it?”

Opined an Instagram user on one review, "You're doing God's work, friend."