Katie Smith's parents took her to five different doctors over four days before an X-ray finally revealed that the two-year-old had swallowed a button battery — and that it was burning through her esophagus.

The two-year-old was rushed to the Hospital for Sick Children for emergency surgery on Friday and is recovering, her mother said.

Anger overshadowed Christina Smith's relief, she said, because the first four doctors sent the family home, telling them their daughter had a cold.

"It was hell, to put it lightly, trying to get the doctors to really listen to us," the Ajax, Ont., mother said. "Her symptoms weren't changing or improving … so we were pretty adamant that we weren't leaving the [last] hospital until we had the answers we needed."

When the X-ray came back early Friday morning at the Rouge Valley Ajax and Pickering Hospital, it showed a small mass lodged in Katie's chest, and she was taken to Sick Kids Hospital in Toronto by ambulance.

Permanent damage

Within an hour of arriving at Sick Kids, Katie underwent surgery, her parents said.

They both said they're thankful they advocated for more investigation, because it minimized the amount of long-term damage done.

"There's going to be some scar tissue for sure and it's probably a bit swollen right now," Smith said. "It's going to take about four to six weeks for it to heal completely."

Fortunately, nothing leaked out of the metal casing, Smith said, an occurrence that has killed dozens of children in the U.S.

Gagging, lethargy, trouble swallowing

The Smiths first noticed Katie gagging on Feb. 8 and took her to Lakeridge Health Oshawa — the Oshawa Hospital — but after a doctor listened to her chest, he said her lungs and airways sounded clear and they sent her home.

"The next day we go to the walk-in clinic," Smith said. "Same thing, they check her airway, they check the back of her throat to see if there's any obstruction back there. Checked her ears, no infections, nothing."

katie smith battery

Katie's dad, Michael Smith, brought her some Popsicles after surgery, some of the first things she's eaten since Feb. 8. (Facebook)

But the little girl couldn't eat, kept drooling and was extremely lethargic, her mother said.

Dr. Dina Kulik said that it's crucial for parents to watch for those symptoms. Roughly 65 children a year are taken to hospital after swallowing a button battery, Health Canada reports.

"If the child is coughing or choking or having difficulty eating … you should seek the advice of your doctor," the Toronto pediatrician said. "Batteries and certain kinds of magnets are the two big ones that we always worry about."

'Go for your 2nd opinion'

Batteries conduct a charge inside the body, which can burn and permanently damage the esophagus, the stomach and the intestines, she said. Magnets can also be attracted to each other, which can tear or damage the gastrointestinal system, too.

Smith said that Katie seems to be on the mend, eating Popsicles, and she should have limited effects from the battery.

But the mother said she hopes other parents will advocate for their children's health.

"You know your child better than anybody else," she said. "So if you don't believe that your doctor is getting the answers that you need, go for your second opinion, your third opinion, whatever you need."