FIVE-year-old Cameron Valks has learned a vital lesson about money - do not swallow it.

The young boy terrified his parents by accidentally ingesting a $1 coin that was stuck in his stomach for seven days.

Cameron's mum Kylie ­Devine said the drama started last Friday after her son got his hands on the coin and started playing with it in the loungeroom of their home, just outside Gunnedah, in northern NSW.

"He had the coin and he put it in his mouth; he started to choke on it and his dad tried to get it back, but then he swallowed it," Ms Devine told The Sunday Telegraph.

Panicked and frightened, Ms Devine rushed Cameron to Gunnedah Hospital where doctors conducted an X-ray, finding the coin, about 3mm wide and 25mm across, in his stomach. But not much could be done except wait for it to come out naturally.

The problem, however, was that the stubborn coin refused to budge, ever after Cameron's many trips to the bathroom. A last resort option would have been to surgically remove the dollar.

"For seven days it was stuck in his system," Ms Devine said, adding that she dutifully checked for signs of the wayward dollar to no avail.

"We took him for another X-ray on Christmas Day and it showed the coin hadn't moved," Mrs Devine said. The coin finally, and painlessly, left the young boy's body two days ago, perhaps spurred on by a big Christmas lunch.

While the extra weight of a coin in the stomach might bother most people, its presence was mostly welcomed by Cameron. For seven days he was able to call himself the "boy money box" and he even used a metal detector, given to him as a Christmas present, to try scan his stomach for the piece.

"I caught his brother scanning Cameron's stomach to see if they could detect the coin," Mrs Devine said.

The family has made a decision to keep the now-washed and cleaned dollar, which has been in circulation since 2011.