The formation of a post-appendicectomy fistula is rare but devastating. Major etiological factors include leakage from the appendiceal stump, neoplasm of the appendix and/or cecum, infection, inflammatory bowel disease, and distal obstruction. The management of enterocutaneous fistula involves enteral nutrition, drainage, antibiotic coverage, as well as surgical excision and segmental resection of the involved bowel. Here we present a case where a young female suffered from refractory enterocutaneous fistula after appendicectomy. Despite extensive treatments, her symptoms persisted and contradicted with objective test results. Therefore, a diagnosis of factitious disorder was suspected. After questioning, she finally admitted to having applied feces to her wound to fake fistula. It was estimated that the lifetime prevalence of factitious disorder in the general population was 0.1%, which warrants the awareness of clinicians.