Patients have accidentally swallowed bread bag clips.
Surgeons are renewing their call for a redesign of the common bread bag clip, after a man required surgery after unknowingly swallowing one.
They say the plastic jaws of the clip, used to tie the tops of bread bags throughout the nation, can easily lodge in the small intestine if accidentally swallowed.
An Adelaide University paper, published in the Australian and New Zealand Journal of Surgery, highlighted the case of a man, 47, who suffered abdominal pain for two months.
A three-dimensional scan of his abdomen revealed a plastic bread clip inside his small intestine, but he had no memory of swallowing it.
Professor Guy Maddern, head of the university's Discipline of Surgery, said doctors hoped the clip would pass through the man, but his pain increased and he required surgery.
"We found that the jaws of the plastic clip had firmly wedged themselves into the wall of the small intestine, causing obstruction and swelling," he said on Thursday.
He said this is an uncommon but recurring problem, leading to bowel obstruction after mainly elderly patients accidentally swallowed clips.
"There have been previous reports of gastrointestinal bleeding being caused by bread clips, and in rare cases there have been fatalities," he said.
"Given that most cases of accidentally swallowing bread clips occur in elderly patients, and we have an ageing population, the food industry needs to cater for this and redesign the clips so they pose a reduced risk.
"There was an impassioned appeal for this redesign over eight years ago, with no result, and cases are still occurring."