Rationale:Infectious diseases, autoimmune diseases and vascular diseases can lead to intestinal ulcers, and inflammatory bowel disease is typically suspected as the underlying cause of ulcer and bleeding from the intestinal ulcers leading to bloody stool, and malnutrition. Here we report a rare case of successfully treated case of intestinal ulcer, bloody stool, and malnutrition by dietary modification and avoidance of long term barbecued spicy food and carbonated drinks.Patient concerns:A 15-year-old male patient had repeated symptoms of blood in the stool for >10 years. Treatment for Chron’s disease was not successful. An exhaustive investigation failed to confirm the diagnosis.Diagnosis interventions:Through changing diet structure, avoiding spicy food, and supplementing enteral nutrition and recurrent glutamine.Outcomes:The patient’s symptoms improved significantly, and the intestinal ulcer healed under endoscope.Lessons:Pay attention to healthy diet in life and avoid long-term consumption of spicy food and carbonated drinks.