'Grey's Anatomy' star Chandra Wilson opens up about her daughter's mysterious illness

— -- Actress Chandra Wilson, who plays a doctor on ABC's long-running hit drama "Grey's Anatomy," opened up about her family's real-life medical saga in an interview with "Good Morning America" that aired today.

Wilson, who has played Dr. Miranda Bailey on "Grey's Anatomy" for the past 13 seasons, described the uncertainty and fear she faced when her daughter, Sarina McFarlane, 23, first became ill as a teenager.

The Emmy-nominated actress said her daughter became afflicted with nausea, vomiting and crippling abdominal pain. McFarlane's mysterious illness baffled doctors, and Wilson said they went nearly 10 months before she finally got a diagnosis -- cyclic vomiting syndrome, or CVS, a neurological disorder characterized by a series of prolonged attacks of severe nausea and vomiting, with no apparent cause.

"It presented itself like a real bad case of food poisoning," Wilson explained. "It didn't go away for four or five days so because of that we went to the ER."

Wilson said emergency room doctors hydrated her daughter but none of the tests showed it was anything different.

"A month later, the exact same presentation happened and this was month after month after month for 10 months," she said.

Wilson kept a running log of her daughter's symptoms in multiple, 5-inch thick binders to note any progress or changes and to streamline the often-arduous check-in process at hospitals.

"I started looking for patterns," Wilson said. "When you are the parent of someone who is a chronic pain sufferer, you end up creating these binders for all of the hospital stays so you can keep track of every visit and any new thing that comes out."

Dr. Richards Boles, medical director at Courtagen Life Sciences -- a medical facility that specializes in genetic testing to find solutions for complicated neurological and metabolic diseases -- said McFarlane could have suffered years had it not been for her mom's tenacity.

"Serena was lucky because of the care and persistence of her mother," Boles said. "Most patients go many years without a diagnosis."

"The name gave us a direction to go in," Wilson said of receiving the diagnosis. "And it put us in a community of other people that seriously were going through the exact same thing stage by stage."

Motivated by her daughter's condition, the "Grey's Anatomy" star went one step further and directed an episode that mirrored her own scramble for a diagnosis for this mysterious disease.

"Being able to be on 'Grey's Anatomy' with all of those people able to watch it and hear it and say, 'Oh my God. That's what that is. I've heard of that. That's my kid. That's my husband. That's my aunt,'" Wilson said. "That means so much because I just remember what it meant to us."

She added, "[If] that's something that I can do sitting in this chair on the set, then my daughter has said, 'Go ahead. Go and do that.'"