Sarah Michelle Gellar's 4-year-old son, Rocky James Prinze, was rushed to emergency room on Jan. 13 after he was having trouble breathing due to a "nasty virus."

After spending the night in the ER, Rocky has now been released.

The actress detailed her son's struggle on Instagram while showing a photo of his hospital bracelet.

"Well I made it 7 years before I had to take one of my children to the ER (I think that's a pretty good stretch) It was a long night and apparently a nasty virus, but thankfully Rocky was released," she wrote. "I'm not going to lie, watching your child not be able to breathe, is the most helpless I have ever felt."

Sarah also revealed that Rocky was doing well with a little help from his friend Inspector Gadget.

"Thank goodness for #iphones and #inspectorgadget when your little one is sick in the ER," she tweeted, adding, "He's better and resting at home now #nastyvirus."

The "Buffy the Vampire Slayer" star was gracious after her little one was given the all clear.

"Thank you to all the great doctors and nurses (and staff) who work tirelessly 24 hours a day to help. And thank you to his big sister, Charlotte who would not leave his side," she said.

Sarah said there was some humor in the hospital, as well.

"The best moment was when I was filling out his paperwork, and I was asked if Rocky was single," she wrote. "Laughter is definitely a great medicine."

The actress and her husband, Freddie Prinze Jr., also share 7-year-old daughter Charlotte Grace Prinze.

They're relatively private about their children and rarely share images of their kids' faces on social media, though that's not always the case.