Three-year-old Zeke Harrison was waking up with a new liver and a second chance at life.

The youngster, son of Wycheproof truck driver Corey Harrison, has spent his life in and out of hospitals.

He was born on December 7, 2010, with a rare metabolic disorder, maple syrup urine disease.

The disorder prevents the body from breaking down protein.

Since birth, Zeke has been stuck on a strictly controlled diet and endured

countless hospital visits because of the disease, diagnosed in about one in 180,000 infants.

Mr Harrison said Zeke went on a waiting list for a new liver - the only cure for the disease - in May.

On Saturday, December 21, Mr Harrison received a 5am call from a Royal Children's Hospital liver consultant to say there was a donor.

Zeke, who was with his Melbourne-based mother Jazmin Hall at the time, had a chance.

Mr Harrison rushed to the children's hospital to be with his little boy.

"I didn't get down before he went into surgery," he said.

Instead, Mr Harrison waited while surgeons operated for 12 hours.

While there were slight complications, at 1am on Sunday Mr Harrison was able to speak to the surgeon, who confirmed the operation was successful.

"He's pretty much been cured," he said.

"The liver he received had the enzyme he was missing."

Zeke spent Christmas in the intensive care unit and moved into the hospital's Cockatoo Ward, for neuro care, two days later.

Mr Harrison and Ms Hall have explained the surgery to Zeke's older brother, Jacob, 6, but Zeke is too young to understand.

"He's smart enough to know that when he was getting sick he ended up in hospital," Mr Harrison said.

"He's woken up in hospital and he's in all this pain but he wasn't sick."

But it's life outside hospital that really has his family excited.

"It still hasn't hit us yet," Mr Harrison said. "It won't hit us until he's eating a huge cheeseburger."

After a lifetime of dieticians, doctors, blood tests and hospitals, Zeke still has a way to go before he reaches perfect health.

He will spend the next six months adjusting to the new liver.

After that, he will have to take one or two tablets every day for the rest of his life.

But the medication is nothing compared with the new lease on life the new liver will give him.

As a thank you to the Royal Children's Hospital, Mr Harrison and partner Laura Bish will host a second annual fundraiser for the hospital on April 5.

Mr Harrison said last year's event raised $20,000.

They aim to beat that total this year with bands, auctions and attractions at Wycheproof's race centre.

Mr Harrison said people could visit zekesfundraiser.org.au for more information and track Zeke's story on Twitter at @ZekesFundraiser.

He said words could not explain his gratitude to the Royal Children's Hospital.

"I know the four best people ever - the four surgeons," he said.