Numerous studies suggest that in asymptomatic patients, routine follow-up CT is not indicated due to the insignificant findings found on these patients. A 53-year-old man, who denied any underlying disease before, underwent colonoscopy for routine health examination. Sudden onset of abdominal pain around left upper quarter was mentioned at our emergency department. Grade II spleen laceration was found on CT scan. Splenic injury was found few hours later on the day of colonoscopy. It might result from the extra tension between the spleen and splenic flexure which varies from different positions of patients.