A rare case of hemoperitoneum in a young man who performed a diagnostic colonoscopy is reported. The rupture of an epiploic appendix among rectum and colon sigma caused massive bleeding into the peritoneum cavity followed by haemorrhagic shock. Diagnostic and therapeutic colonoscopy has a low rate of morbility; perforation and bleeding are the most common events; hemoperitoneum following colonscopy is usually due to spleen rupture. Among other complications, ileal and cecal volvolus, incarceration of hernias and subcutaneous emphysema are reported.