An unexpected case of necrotising amoebic colitis in a Sydneysider.

We present a case of necrotising amoebic colitis (NAC) from a low-risk demographic in Sydney, Australia. A 75-year-old Caucasian male presented critically unwell with an acute abdomen and sepsis following 4 weeks of constipation and progressive abdominal pain. Computed tomography showed pneumoperitoneum, diffuse right-sided colonic wall thickening with multiple hypodense hepatic lesions. With a working diagnosis of perforated right-sided colonic cancer with liver metastases, the patient underwent an open extended right hemicolectomy. Subsequent histopathology demonstrated amoebiasis in the resected specimen. Despite active treatment, the patient died due to septic shock. As NAC is uncommon in Australia, it is often not considered as a differential diagnosis in the acute abdomen. More common diagnoses such as perforated colorectal cancer are often considered instead. Early recognition and initiation of anti-amoebic therapy, along with complete surgical resection of the affected bowel, are associated with improved survival outcomes.