Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 6 S1 2022 07 06 279 283 Yazdan Ghandi Department of Pediatric Cardiologist, Amir-Kabir Hospital, Arak University of Medical Sciences, Arak, Iran. Nooshin Sadjadei Department of Pediatric Gastroenterology, Amir-Kabir Hospital, Arak University of Medical Sciences, Arak, Iran. Mahya Mobinkhaledi Department of Pediatrics, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran. 2021 01 25 2021 04 12 Kawasaki disease (KD) is a systemic vasculitis of small and medium-sized vessels that mainly influences children under five. In the classic diagnostic criteria of KD, there is no Gastrointestinal involvement. Myocarditis is one of the unusual cardiovascular complications of KD, and there is only a very minority of patients have symptoms suggestive of clinical myocarditis. Case Presentation: We reported a 7-year-old boy admitted with a high fever and bloody diarrhea. The stool exam revealed many white blood cells (WBCs) and red blood cells (RBCs). On the 5th day of admission, we found bilateral cervical lymphadenopathy, bilateral nonexudative conjunctivitis, cracked lips, and maculopapular rashes over the extremities. Echocardiography revealed severe mitral regurgitation (MR) with reduced ejection fraction (EF). We treated the patients with oral high-dose aspirin (100 mg/kg/d) plus intravenous immunoglobulin (IVIG 2 gr/kg). Cardiovascular complications such as acute clinical myocarditis should be highly suspected in any patient KD with persistent bloody diarrhea. https://crcp.tums.ac.ir/index.php/crcp/article/view/464