Get ready to learn everything you never wanted to know about pinworm infections.

Never one to shy away from candid personal stories, Kristen Bell has outdone herself with her latest.

On Sunday’s episode of The Joel McHale Show with Joel McHale, Bell shared a recent experience with anal worms, People reported. Yep, we’re cringing too.

Bell explained that both she and her daughter Delta were infected with pinworms after an infestation at Delta’s preschool. “I’m not here to talk about pinworms, but I will,” Bell quipped, as game as ever to go there. “Was it painful?” McHale asked. “No, but it was very itchy,” Bell replied.

While anal worms certainly aren't the most appetizing of topics, it turns out Bell's experience isn't a dangerous or uncommon one. Here's the lowdown on this down-there issue.

What is pinworm infection and what are the symptoms?

Pinworm infection is caused by a white roundworm with the fancy scientific name Enterobius vermicularis, according to the Centers for Disease Control and Prevention (CDC). While the idea of having pinworms is hard to stomach, pinworm infection isn’t as rare as it sounds; it’s actually the most common type of intestinal worm infection in the U.S., according to the Mayo Clinic, with as many as 50% of kids picking up the infection, the CDC reports.

People catch these parasites by accidentally swallowing their eggs. Once hatched, the pinworms set up shop in the colon and rectum, and female pinworms sneak out and lay eggs on the skin around the anus while a person sleeps, according to the U.S. National Library of Medicine, making things intensely itchy around the anus or vagina. (Oh great, something new to have nightmares about!)

How are pinworm infections spread?

Problem is, scratching is one of the easiest ways to transmit pinworms. “When people who are infected touch their anus, the eggs attach to their fingertips,” the Library of Medicine explains. “They can spread the eggs to others directly through their hands, or through contaminated clothing, bedding, food, or other articles.” Pinworm eggs can live on those surfaces for a disturbingly long two weeks.

Pinworm infections are much more common in kids—which makes sense, as anus scratching is not exactly adult-appropriate behavior. But as Bell’s story illustrates, they can happen to anyone. Infections can spread easily, especially to caregivers and family members.

What do pinworms look like?

Here's where things get really unpleasant: You’ll know you have a pinworm infection just by looking at your stools. “You have to look in their poop,” Bell told McHale. “Sure enough, I wiped [Delta] and saw a little white worm.” Yep, they’re visible—and small, thin, and white, according to the CDC.

The eggs aren't always as easy to spot, so doctors might also ask you to perform what’s called the tape test. "This 'test' is done by firmly pressing the adhesive side of clear, transparent cellophane tape to the skin around the anus. The eggs stick to the tape and the tape can be placed on a slide and looked at under a microscope,” the CDC explains.

Are pinworms serious? And how do you get rid of them?

Luckily, as uncomfortable as all this sounds, pinworm infections don't usually lead to any complications. (Phew.) Many people don’t even have any symptoms. Pinworm infection can be treated with over-the-counter or prescription oral medications, typically given in two doses two weeks apart to help prevent reinfection, according to the CDC.

Doctors typically recommend that everyone in the household of an infected person get treated at the same time. “We all did it,” Bell said of her over-the-counter regimen, “but I don’t think anyone got it but me and Delta.” (Lucky Dax!)

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Reinfection is a definite possibility, so kids should be encouraged not to scratch and keep their fingernails trimmed to prevent eggs from collecting there, the Mayo Clinic suggests. (That goes for adults, too.) Wash bedsheets, undies, and towels in hot water daily to help kill eggs. Have kids bathe in the morning, and wash their bums well; pinworms lay eggs at night, so this can help scrub ‘em off.

If just reading this has you dying to scratch everywhere even though there’s no chance you’ve got a pinworm problem, channel that energy into pinworm prevention. The best technique is an old standby: Wash your hands—especially after changing any diapers, helping your kids in the bathroom, and before eating.