Role of abdominal paracentesis in the differential diagnosis of acute diffuse peritonitis LIU Lian-xin, MENG Xian-zhi. Department of General Surgery, the First Affiliated Hospital of Harbin Medical University, Harbin 150001, China Corresponding author: LIU Lian-xin, E-mail: liulianxin@medmail.com.cn Abstract Acute diffuse peritonitis is a common surgical emergency with complex etiology, which makes its differential diagnosis very difficult. Abdominal paracentesis, a commonly used surgical technique, plays an irreplaceable role in the differential diagnosis of acute diffuse peritonitis. It usually leads to quick judgement of etiology as well as timely and effective treatment.