A man in south-east China had to rush to the hospital at midnight after noticing a mysterious ball-sized lump fallen out of his anus.

Doctors said the lump, which was still attached to his rear, was his rectum and it had lost its attachment to his body, according to reports from China.

They also said the condition, called rectal prolapse, could be caused by the fact that the man had sat on the toilet for more than 30 minutes.

According to the man, he had been playing mobile games while trying to defecate.

A man in China had to rush to hospital after seeing a mysterious lump coming out of his anus

The incident took place in Zhongshan, Guangdong Province, on February 4, according to Kan Kan News.

The patient, whose identity was not revealed, was treated by Dr Su Dan from the gastrointestinal surgery division of The Sixth Affiliated Hospital of Sun Yat-sen University.

Dr Su told the reporter that the man was diagnosed with rectal prolapse, a condition that sees the last part of one's intestines losing its attachment to the body and becoming visible from outside the body.

Dr Su said the patient's situation was severe.

'The patient has had rectal prolapse since he was four years old, but the bulge was able to retract in the past,' said Dr Su.

She added: 'But he did not have the condition treated, so the situation got worse.'

A CT scan from a hospital in Guangdong shows the lump sticking out from the mans' anus

Dr Su said spending too much time on the toilet could weaken one's muscles in the pelvis

The bulge that comes out from the anus can sometimes be retracted back inside the body

A computed tomography (CT) scan showed a ball-shaped bulge outside the patient's anus. The lump had a diameter of 16 centimetres (6.3 inches).

Dr Su said there were bruises and blood spots along the patient's intestinal wall.

According to Dr Su, rectal prolapse usually occurs on children or elderly people. For some young children, the condition could be related to innate dysfunction.

Although the patient has had the condition since early ages, Dr Su added that the cause of the prolapse was the long duration spent on the toilet.

Dr Su said when the patient was trying to defecate, the action could have weaken his muscles in the pelvis.

Surgeons successfully removed the lump from the man on the same day, and the man is now recovering.

Dr Lv, a colleague of Dr Su's, explained to MailOnline that whether one is sitting or squatting over a toilet, the pressure in the abdomen builds up which would force the rectum to stick out as the pelvic muscles are not strong enough to hold.

Dr Lv said for anyone who has had similar situation, they should get the condition treated as soon as possible.