The manner of rectal bleeding of auto-amputated polyps (AP) is similar to juvenile polyps (JP) or Meckel's diverticula (MD). We conducted this study to characterize the clinical spectrum of AP.

Fourteen patients were enrolled this study who were diagnosed AP due to painless rectal bleeding. The clinical data of AP was assessed and then compared with the clinical data of JP and MD retrospectively.

The prevalence of AP was 10.4% (14/135) and high in younger patients compared with that of JP (p=0.042 below 2 years). Whereas JP was more common in patients aged 2 to 5 years (p=0.005). Male was predominant in AP (p=0.008 AP vs JP). The manner of rectal bleeding in AP group was sudden and transient. There was no significant difference in time interval between onset of rectal bleeding and diagnosis between the 3 groups. However AP was diagnosed in 9 patients (64.3%) within 7 days after onset of rectal bleeding, but JP was diagnosed in 5 patients (4.1%) in the same period (p<0.001). All of AP were located in the rectum and the sigmoid colon. The mean hemoglobin was 11.3±1.5 g/dL in AP, 11.8±1.3 g/dL in JP, and 8.4±1.2 g/dL in MD (p<0.001, only significant in MD).

AP may be considered in male older than 1 year with transient and sudden onset or increase of painless rectal bleeding without drop of hemoglobin level.