Subscribe | UPI Odd Newsletter Subscribe LONDON, Sept. 18 (UPI) -- A tiny fish found its way into a teenage boy's body in Britain by traveling up the teen's penis into his urethra, doctors say. Doctors G. Vezhaventhan and R. Jeyaraman, whose full first names were not reported, said the fish apparently entered the teen's body while he was going to the bathroom, The Sun reported Thursday. Advertisement The medical experts, who treated the boy for complaints of pain and urinary retention, said in a paper that the young man made the regrettable mistake of urinating while holding the tiny fish. "While he was cleaning the fish tank in his house, he was holding a fish in his hand and went to the toilet for passing urine," they wrote. "When he was passing urine, the fish slipped from his hand and entered his urethra and then he developed all these symptoms." The animal, thought to be part of the Betta genus, was removed using a medical device designed to remove bladder stones, the Sun said.