BackgroundGastrointestinal (GI) symptoms are commonly observed in patients with diabetic ketoacidosis (DKA), which usually resolves completely with therapy. However, GI symptoms can persist after DKA resolves, which can pose diagnostic and management challenges for physicians, especially when dealing with an exceptional diagnosis such as cannabinoid hyperemesis syndrome (CHS).Case presentationIn this case report, we present a patient with type 1 diabetes who had been treated for DKA 6 times in the past year and was eventually diagnosed with CHS.ConclusionIn conclusion, this case demonstrates that a presumptive and incorrect diagnosis can mislead physicians, especially when dealing with challenging diagnoses. Therefore, patients with type 1 diabetes with unusual presentations, such as unexpectedly high pH and bicarbonate levels, with hyperglycemic ketosis should be screened for illicit drug use, especially cannabis.