A fellow was hospitalized in Xinghua, China after attempting to relieve his constipation by, er, encouraging a 20 centimeter long eel to wiggle into his rectum. Unsurprisingly, it didn't go well. The eel reportedly forced its way deeper into his body and into his abdomen. He was apparently "too shy to see the doctor" at first but the pain convinced him that he was likely in real trouble. A surgeon removed the eel, saving the man's life. Apparently, this is a "folk remedy" that is tried more often than you'd think. From the Global Times:
A 50-year-old man in South China's Guangdong Province did the same thing with a 40 cm-long eel in June 2020. On June 2 2020, an African carp was found in the stomach of a young man in Guangdong, who claimed that the fish "slid into" his rectum when he accidentally sat on it.