At some point you may have come across an odd and frankly horrifying urban legend, which states that if you get your butt caught over a pool drain, your intestines can be – for genuine want of a better way of putting this – sucked out of your anus.
The fact has shown up in everything from It's Always Sunny in Philadelphia to one incredible scene in horror film Final Destination. Unfortunately, the whole thing is true, as confirmed by several high-profile cases in the US as well as cases in the medical literature. One summary of cases, published in the Medical Journal of Australia in 2010, describes the horrendous ordeal three patients went through in Australia.
One of the patients, all of whom were young children, briefly sat on an uncovered drain in a swimming pool at his home. "He extracted himself," the paper notes, "but his intestines could be seen prolapsing from his anus". The 6-year-old underwent what's known as "transanal evisceration", as "110 cm [43 inches] of small intestine had herniated out via the anus". Left with 55 centimeters of intestines, the boy's intestines were shortened and his long-term growth was normal, barring loose bowel motions.
Two other patients had similar stories and outcomes, both losing part of their intestines after accidentally sitting on skimmer boxes in a motel and home swimming pool.
"The causes of these evisceration injuries are well described in the literature. Vortex-style drains can create a powerful vacuum when occluded," the case report reads. "In addition to the transanal route, direct evisceration through the perineum has been described."
The team write that there is evidence that suction drains aren't necessary for cleaning pools, and safer alternatives are also more effective, and called for antivortex covers to be installed on existing pools. Two of the patients suffered their injuries following the temporary removal of such covers. Drains without safety covers can generate 159 kilograms (350 pounds) of suction pressure with standard pumps, according to Pool and Spa News.
"There is considerable morbidity associated with this condition," the team added. "The most minor form of injury can be a transient rectal mucosal prolapse with no perforation, but, even at this end of the spectrum, there is considerable psychological impact."
Injuries caused by drains can be fatal, as in several high-profile cases in the US. In 2007, 6-year-old Abigail Taylor was in the "kiddie pool" at a Minneapolis golf club when she became stuck on an uncovered drain and was "disemboweled by the powerful suction of the pool pump". Following the injury, Taylor was unable to eat normally, and died from cancer related to a liver transplant. Her case led to new national pool safety legislation, setting safety standards for drain covers.
Lobbying by the family of another girl, Virginia Graeme Baker, who drowned in 2002 after becoming stuck to a drain in a hot tub, prompted similar legislation requiring anti-entrapment drain covers and other safety devices to be fitted to pools.