Colonoscopy is a widely used method of screening, diagnosis and intervention. Complications are infrequent and generally present as colonic perforation or colonic hemorrhage. A rare and life-threatening complication of colonoscopy is splenic injury or rupture. We present a case report of an 81-year-old female who was admitted with hemodynamic instability and tachycardia due to gastrointestinal (GI) bleeding and developed hemoperitoneum within 24 hours following colonoscopy. The initial computed tomography (CT) scan was misdiagnosed due to the patient history of GI bleed, and the iatrogenic splenic injury was recognized only during a second CT after continued hemodynamic instability. The patient’s initial diagnosis of a GI bleed masked the intraperitoneal bleed and led to a delayed diagnosis of splenic rupture and increased morbidity. This patient required an emergent laparotomy with a total splenectomy with lysis of adhesions.