we experienced four patients with amebic colitis proven by coloncscopic and sigmoidoscopic biopsy. The results were following. Clinical symptoms, laboratory studies, and radiological findings may not be sufficient for making an accurate diagnosis for amebic colitis. Though the diagnosis of amebic colitis seems to be established easily by identification of amebic trophozoites of Entameba histolytica, it can be difiicult and confusing to differentiate from other forms of colitis if the organisms not be demonstrated. The gross colonoscopic and sigmoidoscopic appearanc as well as the results of its biopsy could be extremely important for arriving at the correct dignosis of amebic colitis.