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Suction-Drain Injury in a Public Wading Pool -- North Carolina, 1991

On June 16, 1991, a 3-year-old girl playing in a public wading pool sat on the pool's uncapped suction drain. The child appeared to be stuck on the drain, and the pool attendant quickly turned off the pool's suction pump. As a consequence of sitting on the drain, the child sustained severe internal injuries requiring surgical repair. This report summarizes the investigation of this incident by the North Carolina Department of Environment, Health, and Natural Resources (DEHNR) and describes safety measures to prevent injuries among children caused by pool suction drains.

Following the episode at the wading pool, the child was examined at a hospital and had perianal bruising and prolapse of the rectal mucosa. The prolapse was manually reduced, and a pelvic computerized tomography scan showed no evidence of a rectal leak; however, by June 17, she had evidence of localized peritonitis. An exploratory laparotomy revealed a long anterior laceration of the seromuscular layer of the rectosigmoid colon; the mucosal tube was intact but ischemic and was separated circumferentially from the outer layers of the bowel wall. The laceration was repaired and a sigmoid colostomy performed.

The investigation by the DEHNR revealed that the wading pool where this injury occurred had a three-quarter-horsepower suction pump that was not linked to the adjacent adult pool or any other outlet. At the time of the injury, the antivortex drain cover that had previously covered the drain had been removed. Since the incident, the antivortex drain cover has been secured to the drain to prevent further suction injuries.

Reported by: NA Shorter, MD, Section of Pediatric Surgery, Duke Univ Medical Center, Durham; JP Woodell, Durham County Health Dept; TB Cole, MD, Injury Control Section, JA Hayes, MSPH, Div of Environmental Health, JN MacCormack, State Epidemiologist, North Carolina Dept of Environment, Health, and Natural Resources. Unintentional Injuries Section, Epidemiology Br, Div of Injury Control, National Center for Environmental Health and Injury Control, CDC.

Editorial Note

Editorial Note: The findings in this investigation are consistent with those from previous reports of abdominal injuries among children who sit directly on uncovered openings or vents capable of forming a strong vacuum when covered (1). When a child sits on an unprotected suction-drain vent, the child's perineum can form a firm seal that creates a vacuum capable of relaxing the anal sphincter. This negative pressure on the exposed rectal walls can result in prolapse or intussusception; this, in turn, usually produces a full-thickness anterior bowel tear, creating the potential for evisceration of the mobile small intestine through the laceration and the anal canal. Damage to the mesentery can produce extensive irreversible small bowel ischemia requiring resection.

Since May 1, 1991, North Carolina has required all newly constructed public wading pools to be equipped with a surface skimmer and with interconnected double drains to prevent suction-drain injuries. However, pools constructed before May 1, 1991, have been allowed to continue operating with a single drain. The public pool involved in this incident was built before the standards became effective; however, the pool had been inspected 12 months before the injury occurred and had had an antisuction cover in place over the drain opening at that time.

Because a child may be injured within seconds of sitting on a drain, adult supervision alone does not effectively prevent suction-drain injuries. Suction-drain injuries can be prevented through interventions that prevent vacuums from forming when the vents are covered. Existing pools that may have a single suction-drain or multiple suction-drains that can be isolated by valves should be equipped with antivortex covers or with grates at least 12 inches by 12 inches over the drains to prevent the possibility of a vacuum forming if a child sits on a suction-drain opening (2). In addition, standards of the American National Standards Institute/National Spa and Pool Institute and the American Public Health Association specify that drain covers be secured in a way to prevent removal without special tools (2,3). Also, maintenance personnel should routinely inspect pool drains to ensure covers remain secure. Pools should not be operated if a suction-drain cover is missing, broken, or inadequately secured (2).

For new pools, water circulation systems should be constructed so that suction pumps are linked with more than one drain outlet; for example, the pump may draw water from two drains in the deepest part of the pool or from one drain and a surface skimmer, thus preventing a tight seal from forming if one drain is covered. In addition to these barriers, water-safety instruction courses should include specific instructions on the prevention of injuries involving pool equipment.


  1. Cain WS, Howell CG, Ziegler MM, Finley AJ, Asch MJ, Grant JP. Rectosigmoid perforation and intestinal evisceration from transanal suction. J Pediatr Surg 1983;18:10-3.

  2. National Spa and Pool Institute. American national standard for public swimming pools. Alexandria, Virginia: American National Standards Institute, National Spa and Pool Institute, 1991; publication no. ANSI/NSPI-1 1991.

  3. American Public Health Association. Public swimming pools: recommended regulations for design and construction, operation and maintenance. Washington, DC: American Public Health Association, 1981:16-7.

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