Not eating, throwing up and losing weight are all clear signs of an eating disorder. So it was no wonder when family members, friends and doctors thought that 14-year-old Gentrie Hansen had one after she lost 30 pounds in seven months.
The difference with Gentrie's symptoms is that she wanted to eat. "I would gladly take some weight and then be healthy and be happy," Gentrie told TODAY's Ann Curry in an interview. But even a small bite of food or beverage would make her throw up.
She was experiencing what doctors later found out was gastroparesis -- a rare neurological disease where the stomach doesn't empty properly. "The nerves and the muscles aren't coordinated so food goes into the stomach and can't get out, so the only way to get it out is through vomiting," said NBC's chief medical examiner, Dr Nancy Snyderman.
After dozens of failed therapies and medications doctors inserted a pacemaker into Gentrie's stomach. "It works like a pacemaker for the heart sending signals to nerves so the muscles will work normally," says Dr. Snyderman.
"It was really frustrating having people tell me I had an eating disorder when I knew I had a disease," says Gentrie. "It was the worst part of the sickness."
Having an actual diagnoses was a blessing and a curse for the Hansens. "You're so glad there's something to go forward with and try to understand, but at the same time you realize it's a lifelong disease without a cure," says Gentrie's mom.
WATCH:
Visit msnbc.com for breaking news, world news, and news about the economy