Abstract
BACKGROUND: Enteric-coated Mycophenolate Sodium(EC-MPS), one preparation of Mycophenolic acid(MPA), is an immunosuppressive drug commonly used after liver transplantation to prevent allograft rejection. EC-MPS induced small bowel ulcers are very rare and have not been reported in liver transplant recipients. Herein, we report two patients considered with small bowel ulcers induced by EC-MPS (a diagnosis of exclusion). CASE PRESENTATION: Case 1: A 56-year-old male complained of melena 40 days after orthotopic liver transplantation. Emergency esophagogastroduodenoscopy and colonoscopy did not find bleeding sites. His hemoglobin level was 47 g/L. Further small bowel endoscopy revealed an ulcer. EC-MPS was discontinued, and the small bowel capsule endoscopy showed the small bowel ulcer was completely healed 10 days later. The patient recovered well, and there was no melena during a follow-up period of 7 months. Case 2: Another 56-year-old male complained of melena 21 days after orthotopic liver transplantation. Emergency esophagogastroduodenoscopy and colonoscopy revealed mild esophageal varices and did not find active bleeding sources. His hemoglobin level was 68 g/L. Further small bowel endoscopy showed multiple large, irregular ulcers. Based on the clinical experience of managing case 1, EC-MPS was discontinued and substituted with mycophenolate mofetil (MMF). Then gastrointestinal hemorrhage was resolved, and enteral nutrition was gradually restored. Unfortunately, the patient ultimately died of a life-threatening infection. CONCLUSION: Although usually regarded as a diagnosis of exclusion, liver transplantation recipients presented with small bowel ulcer need to be vigilant about the possibility of side effects of immunosuppressive agents, especially EC-MPS. Timely identification and adjustment of medication may improve the clinical outcome of patients. Heightened clinical awareness of this pharmacological association is strongly advocated. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12893-025-03354-1.