No one knew why Ollie couldn’t stop vomiting. Then his mum made a frightening discovery.

When one-year-old Ollie Lennon began violently vomiting black fluid, his parents had no idea what was wrong with him. Chrissy Lennon and husband Elliott consulted a doctor, who told them to keep an eye on Ollie. But the next morning he was still sick.

It was only when Lennon, who had just started a diet, went to weigh herself that she worked out what must have happened. The bathroom scales didn’t work because the button battery was missing. Lennon realised Ollie must have swallowed it, and rushed him to hospital near their home in West Sussex.

Surgeons eventually managed to remove the battery, which had lodged in the lower part of Ollie’s throat, but it had corroded. The little boy had scarring and acid burns to his trachea. He was placed in an induced coma.

Lennon took to Facebook to ask people to sign and share a petition to encourage battery manufacturers to support the development of safer batteries.

“A couple of weeks ago we were celebrating Ollie’s first birthday,” she wrote. “Now he’s lying in a hospital bed, attached to lots of cables, and this morning was on a ventilator!

“Don’t let what we are going through happen to anyone else! I knew all the warnings and still could not protect my son! Kids put everything in their mouths and no matter how guilty I feel, I couldn’t have done anything, without having eyes in the back of my head! I wish I had! Heartbroken.”

After several days, Ollie was brought out of his induced coma. But then his lung collapsed and his condition rapidly deteriorated. He was transported to Great Ormond Street Hospital in London and prepared for more surgery. The Lennons were told he had just a one-in-10 chance of survival.

Thankfully, Ollie pulled through. He was kept in an induced coma for another week.

Finally, in mid-July, after two months in hospital, Ollie was allowed to go home.

“Stopping even just one family going through this would really help and be amazing,” Lennon posted on Facebook. “I have never cried as much in my life, and there is no worse feeling than seeing your child in pain and being able to do nothing about it!”

Ollie’s parents are now fundraising for Great Ormond Street Hospital, and have organised a charity football match for next month.

“We want to raise as much money as possible, as they have saved Ollie’s life,” Lennon adds.

In Australia, 20 children are taken to hospital emergency departments each week after swallowing button batteries or inserting them into their noses or ears.

Susan Teerds, CEO of Kidsafe Queensland, says bathroom scales are among the household items that commonly contain button batteries. Others include remote controls, torches “and promotional items like tealight candles and flashing jewellery, especially around Christmas”.

“A child in Sydney swallowed a battery Dad had taken out from his bicycle light and left on the counter,” Teerds tells Mamamia. “It was flat, but a flat lithium battery can still kill once it stops moving in the child’s throat.”

Teerds said it was “unusual” for Ollie to be vomiting black fluid.

“Unless you see the child swallow the battery, the symptoms don’t give you much of a clue as to what has happened,” she points out. “They can have a bit of a cough, be upset, drool, cough like croup and refuse solid food (but often not liquids). Even the doctors and emergency staff have difficulty diagnosing a battery ingestion.”

Teerds believes that more than one solution is needed. These include changes to battery packaging, products being made with “locked-down” battery compartments, and changes to batteries themselves.

“And finally, for schools, churches, etc to stop using cheap, flashing rubbish with button batteries as fundraisers!”

Would you know what to do if your child swallowed a battery?

LISTEN: Holly Wainwright and Andrew Daddo dissect what parents are talking about this week on This Glorious Mess (post continues after audio...)