Amoebic dysentery is designated a Category 5 disease under the Infectious Disease Control Law in Japan, with approximately 1,000 cases reported annually. About 10% of these are cases of invasive amoebic dysentery, 90% of which have an asymptomatic course and are often discovered incidentally, and there is concern that the number of undiagnosed cases is increasing since the reagent for that blood antibody test was discontinued in 2017. Invasive amoebic dysentery often causes ulcerative lesions that affect the cecum and rectum predominantly, but eradication of amoebic dysentery is possible with proper diagnosis and treatment. However, there have been cases in which delayed diagnosis and treatment have resulted in fulminant forms of colorectal ulceration, including perforated peritonitis and amoebic liver abscesses. In this report, the importance of the diagnosis and treatment of this disease is reiterated, and a case that was difficult to diagnose is presented.