The tip of the iceberg of colorectal perforation from enema: a systematic review and meta-analysis

Background: Although rare, perforation following an enema used to treat constipation is a dangerous complication. However, no recommendations or guidelines for enema use are available. So, in common clinical practice, the diagnostic approach and the treatment are not standardized. In an attempt to resolve this clinical dilemma associated with high mortality and potential medicolegal claims for malpractice, we have performed a systematic review and meta-analysis of studies reporting on colorectal perforation secondary to enema use for adult patients with constipation. Methods: A systematic search of PubMed, Web of Science and Scopus was performed according to the PRISMA statement up until February 2020. Studies that reported on colorectal perforation from enema use in adult patients with constipation were included. The primary outcomes were the rate of hospital mortality and pooled prevalence estimates of mortality from perforation secondary to enema use. The secondary outcomes were the administration of rectal enemas, site of visceral perforation, signs, symptoms, radiological evaluation, and type of treatment Results: A total of 15 studies were included in the final analysis (49 patients). Across all studies, the pooled prevalence estimate of mortality for patients with perforation secondary to enema use was 38.5%, (95% CI [22.7%, 55.5%]). This rate was lower in patients who had surgery (35%) than in patients treated conservatively (57.1%). The sites of perforation were intraoperatively reported in 84% of cases, but in 16% of patients the rectal perforation was undiagnosed, and surgical decision making was problematic. The primary location of the perforation was the rectum in 80.9% of the patients. The enema was administered by a nurse in 90% of the cases, self-administered in 7.5% and a family doctor in 2.5%. The main objective of emergency surgery in this setting is resection of the perforation caused by the enema; when it is not possible to resect the perforated rectum, faecal diversion is needed. Hartmann’s procedure was most commonly performed by the surgeons in this review (60.7%), with other reported treatments included a diverting proximal loop colostomy and sigmoid segment exteriorization Conclusions: Considering the studies available, it is not possible to undertake a thorough evaluation of enema use, including the associated complications and their management. Further data are required to allow the development of guidelines to advice on safe enema use and management of complications