An elderly man in Cambodia was left in agony after a leech entered his body through his penis.
Surgeons discovered the creature inside the unnamed man's bladder after he travelled to hospital because he was suffering pain when trying to urinate.
Medics questioned the patient, who revealed that he had stripped off and gone for a swim in the river.
It's thought that the leech travelled up his urethra and into his bladder. It then latched on and drank a pint of his blood, which caused the leach to rapidly expand in size.
Doctors at the hospital in Phnom Penh have warned people to be vigilant when swimming in ponds while leeches are active.
The hospital said in a statement: ''The waters are rich with leeches and other insects during the rainy season.
''Consult with the specialists immediately if you are experiencing pain in your body to get it treated correctly.''