Chronic Hematochezia Caused by Amoebic Colitis with Multiple Flask-Shaped Colonic Ulcers: A Case Report
Chronic hematochezia is a clinical presentation with a broad differential diagnosis. Among infectious causes of hematochezia, amoebic colitis due to Entamoeba histolytica requires early consideration, particularly in tropical and endemic regions. However, the diagnosis of amoebic colitis is often challenging due to the limited sensitivity of stool examination, leading to delayed treatment. Therefore, this case report aims to explore the limitations of stool examination and emphasize the important role of colonoscopy and histopathology in establishing the diagnosis of amoebic colitis in patients with persistent symptoms. The diagnostic challenge was shown by the case of a 49-year-old man presenting with hematochezia for more than one month, accompanied by intermittent fever and abdominal bloating. Initial stool examination showed numerous erythrocytes and leukocytes, but no trophozoites or cysts of E. histolytica were identified. Due to persistent symptoms, colonoscopy was performed and showed pancolitis with multiple large irregular ulcers covered with friable debris that bled easily throughout the colon. Histopathological examination confirmed the presence of flask-shaped ulcers containing amoebic trophozoites, establishing the diagnosis of amoebic colitis. The patient was treated with metronidazole 750 mg three times daily for 10 days, resulting in complete resolution of hematochezia. This case showed that a negative stool examination did not exclude amoebic colitis. In patients with high clinical suspicion and persistent symptoms, colonoscopy and histopathological evaluation played a crucial role in confirming the diagnosis and enabling timely treatment. This report also showed the importance of a comprehensive diagnostic method to prevent delays in the management of amoebic colitis in endemic regions.