In lupus enteritis, circulating pathological immune complexes and thrombosis of intestinal vessels may occur, resulting in acute abdominal pain. We report a 24-year-old woman without a history of systemic lupus erythematosus (SLE), admitted for abdominal pain. An exploratory laparotomy found an appendicitis along with ascites. An appendectomy was performed, and the patient was released from the hospital two days later. Three days after discharge, the patient was admitted to another hospital due to the persistence of abdominal pain. An abdominal computed tomography scan showed diffuse mesenteric congestion, concentric bowel loops (double halo or target sign) and the presence of free fluid in the peritoneal cavity. Suspecting a rheumatic disorder, the diagnosis of SLE was confirmed by immunological studies. The patient was treated with pulses of methylprednisolone with good results.In lupus enteritis, circulating pathological immune complexes and thrombosis of intestinal vessels may occur, resulting in acute abdominal pain. We report a 24-year-old woman without a history of systemic lupus erythematosus (SLE), admitted for abdominal pain. An exploratory laparotomy found an appendicitis along with ascites. An appendectomy was performed, and the patient was released from the hospital two days later. Three days after discharge, the patient was admitted to another hospital due to the persistence of abdominal pain. An abdominal computed tomography scan showed diffuse mesenteric congestion, concentric bowel loops (double halo or target sign) and the presence of free fluid in the peritoneal cavity. Suspecting a rheumatic disorder, the diagnosis of SLE was confirmed by immunological studies. The patient was treated with pulses of methylprednisolone with good results.