Abstract
Type 1 diabetes (T1D) is an autoimmune disease characterized by pancreatic β-cell destruction and absolute insulin deficiency. In pediatric patients, T1D typically presents with classic symptoms such as polydipsia, polyuria, weight loss, or diabetic ketoacidosis (DKA). Although gastrointestinal symptoms may occur at disease onset, paralytic ileus as an initial manifestation of T1D, particularly in the absence of DKA, is extremely uncommon. A 15-year-old boy presented with severe abdominal pain and vomiting and was diagnosed with paralytic ileus based on abdominal radiographic findings. Mild hyperglycemia at initial presentation was initially interpreted as transient. Conservative management led to improvement in gastrointestinal symptoms; however, persistent glycosuria was noted. After discharge, marked polydipsia and weight loss developed. Subsequent evaluation revealed severe hyperglycemia and elevated hemoglobin A1c (HbA1c) levels. Endocrinological assessment demonstrated positive anti-glutamic acid decarboxylase and anti-insulinoma-associated antigen-2 (IA-2) antibodies with reduced endogenous insulin secretion. Autoimmune T1D without DKA was diagnosed, and intensive insulin therapy was initiated, resulting in stable glycemic control. Paralytic ileus preceding the diagnosis of new-onset autoimmune T1D without DKA is an exceptionally rare presentation in pediatric patients.