At first glance, its white, curved appearance may make you think it's an egg. But it's not.
The object got trapped in a teen's intestine after he put it in his anus — and doctors struggled to get it out.
The 14-year-old, from Australia, panicked when he realised he couldn't retrieve it or push it out.
He owned up about his blunder — which happened with a golf ball — to his mother, who whisked him to the nearest emergency department.
Medics at the Royal Adelaide Hospital were told that it was not causing him any pain.
The boy, who wasn't identified, also confessed that he had unsuccessfully tried to expel the ball by defecating.
X-ray scans showed it had made its way to his sigmoid colon, the last part of the large intestine, which connects to the rectum.
Doctors tried to remove the golf ball using six different retrieval devices, including a suction cup, medical net, quad-prong grasper and a balloon catheter.
After two hours, medics gave up with 'aggressive' interventions, hoping the golf ball would come out on its own.
However, an X-ray performed 24 hours later showed it was still there.
With the family reluctant for the boy to undergo anymore physical removal attempts, doctors decided to trial administering a large quantity of laxatives.
The boy was given one litre of laxatives — resulting in the 'successful evacuation' of the golf ball three hours later.
'Following passage of the golf ball, the patient remained clinically well and was discharged the same day,' the researchers said.
'There was no evidence of bowel injury.'
They added that the boy was 'advised against inserting further objects into his rectum in the future'.
Doctors concluded: 'A golf ball presents unique technical challenges when attempting to remove from the colon due to its mechanical properties.
'These include its large size, spherical shape, incompressibility, and the presence of dimples, which prevents a suction seal.'
They added that future patients with foreign bodies inside them, where there is no obstruction of bowel function, should first be given laxatives in order to encourage the object to pass by itself.
The case was reported in the Case Reports in Surgery journal.