Acute appendicitis complicated by a rare double appendix: a rare anatomical anomaly

Acute appendicitis is one of the most common emergency general surgery presentations. However, a duplicate appendix is very rare, in an incidence of 0.004%-0.009% and is challenging to diagnose. It is often diagnosed intraoperatively during laparoscopy or more commonly in laparotomy. A duplicate appendix causing appendicitis can lead to a more complicated presentation, such as perforation. We present a case of a man in his late 70s, who presented with complicated acute appendicitis due to the presence of a double appendix. Both appendices were inflamed, with one having perforated with the presence of a faecolith, leading to an abscess cavity in the right iliac fossa. This case adds to the body of literature on duplicate appendix and emphasises the importance of identifying this anatomical anomaly.