"You have to look in their poop — and sure enough, I wiped and saw a little white worm," says Bell

Another day, another glorious parenting story courtesy of Kristen Bell.

The actress was a guest on Sunday’s episode of The Joel McHale Show with Joel McHale, a weekly half-hour distillation of the week’s funniest pop culture moments that recently premiered on Netflix. During her appearance, the mother of two somehow found herself on the topic of — wait for it — anal worms, and PEOPLE has your exclusive look at the off-the-cuff moment.

“I did have anal worms two weeks ago — I swear to God,” Bell, 37, told McHale, 46. “They’re called pinworms. My kids had them.”

“Was it painful?” asked McHale.

“No, but it was very itchy,” she said. “I’m not here to talk about pinworms, but I will. Fifty percent of people over 15 don’t experience symptoms, which is the itch. Your kids get them because they put their hands in their mouth and they lay eggs.”

Bell, who shares daughters Lincoln, 4, and Delta, 3, with husband Dax Shepard, went on to explain that she showed up at her daughters’ preschool one day and noticed all the carpets were gone. Turns out, they were being cleaned because a case of pinworms had broken out.

“Of course I immediately Googled it, and it’s like so, so contagious,” she said. And ‘lo and behold, she noticed that Delta had started scratching … down there.

“You have to monitor, and you have to look in their poop,” she said. “And when you wipe their butt, sure enough — I wiped, and saw a little white worm. I know, she’s really gross. My daughter, not the worm. The worm was gross, too.”

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Soon enough, Bell got “the itch” herself, and the whole family had to take an over-the-counter treatment.

“We all did it, but I don’t think anyone got it but me and Delta,” she said — before reaching out to give McHale the most enthusiastic of handshakes.

“Good to be here, Joel!” she quipped.

Catch the full episode of The Joel McHale Show with Joel McHale featuring Bell, streaming now on Netflix.