(File photo) The eel which was removed was reported to be half a metre long Reuters

Doctors in China have removed a live eel from a middle-aged man who inserted it inside himself while following an apparent folk remedy for constipation, according to reports.

The man underwent an operation in Guangzhou to remove to fish after inserting it in his anus. He had reportedly heard live eels could cure his condition, according to the Guangzhou Daily.

The man was hospitalised after complaining of pain in his stomach and intestines.

Chinese media said doctors described the man's stomach as "inflated like an air balloon", adding the half-metre long eel had broken through the intestines and generated "a mess" in his abdominal cavity "almost killing him".

A second doctor said the eel the man used to treat his constipation had a "head as large as a ping-pong ball".

Unconfirmed photos from Chinese media appear to show the eel once it has been removed from the man, who is now recovering from the incident.