Lupus Enteritis Presenting as Acute Abdomen with Clear Gelatinous Stools in a Woman with Systemic Lupus Erythematosus: A Case Report and Literature Review

Abstract Lupus enteritis is a recognized but uncommon and potentially life-threatening gastrointestinal manifestation of systemic lupus erythematosus. Its symptoms are often nonspecific and may mimic infectious enteritis, pseudomembranous colitis, intestinal obstruction, or a surgical acute abdomen. We report a 19-year-old woman with a prior diagnosis of SLE and irregular use of maintenance therapy who developed abdominal pain, watery diarrhea, nausea, vomiting, and progressive abdominal distension after ingestion of suspected contaminated food. During hospitalization, she passed large amounts of clear, gelatinous, pseudomembrane-like stool material. Laboratory evaluation showed anemia, thrombocytopenia, hypocomplementemia, positive antinuclear antibodies, positive anti-Ro52 antibodies, and negative microbiological studies, including stool culture and Clostridioides difficile toxin assays. Contrast-enhanced abdominal computed tomography demonstrated segmental small-bowel wall thickening with the target sign, mesenteric vascular engorgement with the comb sign, and ascites, supporting the diagnosis of lupus enteritis. After infection was considered unlikely, empirical antibiotics were discontinued. High-dose intravenous methylprednisolone, adjunctive intravenous immunoglobulin, and cyclophosphamide led to rapid clinical improvement within 48–72 hours, with subsequent radiological resolution. The novelty of this case lies not in lupus enteritis itself, but in its presentation with substantial clear gelatinous pseudomembrane-like stool material, a rarely emphasized manifestation that may mislead clinicians toward infectious or pseudomembranous colitis. Early recognition based on SLE activity, characteristic CT findings, exclusion of infection, and multidisciplinary assessment is essential to avoid diagnostic delay and prevent severe complications.