We report the case of a 32-year-old female patient who presented with worsening symptoms of bloody diarrhea, abdominal pain, and fever. Based on the clinical presentation, colonoscopy findings, and CT imaging, the patient underwent colectomy for suspected intestinal perforation. Histopathological examination and immunohistochemistry analysis of the resected specimen ultimately led to the diagnosis of primary intestinal NK/T-cell lymphoma.