Difference in Outcomes of Rectal Foreign Bodies between Males and Females: A Retrospective Analysis of a National Inpatient Database in Japan

<b><i>Background/Aims:</i></b> Almost all previous studies related to rectal foreign bodies were based on bizarre and striking cases, resulting in a reporting bias. Our aim was to clarify the clinico-epidemiological findings of rectal foreign body (RFB) in a general population. <b><i>Methods:</i></b> Using a national administrative database in Japan, we identified patients who underwent in-hospital treatment for rectal foreign bodies from 1 July 2007 to 31 March 2013. <b><i>Results:</i></b> A total of 648 RFB patients with 666 presentations were identified during the study period. The number of male patients was 526 (81.1%). The incidence of a RFB was most frequently seen in males who were in their 60s and in females who were in their 80s. The overall in-hospital mortality was 1.2%. Compared with males, females had a significantly higher proportion of in-hospital death (0.4 vs. 4.8%, p = 0.001), perforation and peritonitis (5.2 vs. 12.8%, p = 0.004), and sepsis (1.1 vs. 4.0%, p = 0.04). <b><i>Conclusion:</i></b> This study showed the clinico-epidemiological findings of rectal foreign bodies in a general population, and established that there was a low mortality rate. It was also found that females were significantly more likely to have a severe outcome following a RFB than males.