Backgrounds: The prevalence of inflammatory bowel disease (IBD) in worldwide exceeded 0,3%. The highest prevalence of Crohn’s disease is reported in Germany (322 per 100.000). The incidence and prevalence of IBD relatively low in Asia. In Indonesia, the case of IBD are rarely found. Reported a 5.2% of cases of Crohn’s disease and from the rest of the total cases colonoscopy at Cipto Mangunkusumo Hospital. In majority population, patients with Crohn’s disease usually diagnosed in their 20s and 30s. However, 5-10% of all cases occur early in pediatric.
Case Illustration: A 17 years old had reccurent bloody stool, recurrent diarrhea, recurrent stomatitis, pale, abdominal pain, weight loss, and did not have her period since 16th years old. Physical examination showed cachexia appearance, old man face, prominent costae, tenderness at abdominal palpation, muscle wasting, severe malnutrition, and puberty stage Tanner III (M3P2). The laboratory findings revealed micrositic hypochromic mild anemia, FOBT (+),  faecal calprotectin >2.100 ug/g, and hypoalbuminemia. The abdominal CT scan revealed with suspect inflamation process in the intestine. The colonoscopy and esophago-gastro-duodenoscopy (EGD) finding revealed multiple ulcus colon with skip lesions and pangastritis superficialis. The histopathologic finding revealed an active chronic gastritis and colitis. Patient got enteral nutrition with minimum duration 6 weeks, corticosteroid to induce remission for ten weeks (include tapering dose), omeprazole, antibiotic for urinary tract infection, albumin, vitamin and micronutrient for malnutrition management. After 10 weeks of treatment she experienced clinical improvement. 
Conclusion: Crohn disease in adolescent girl and associated manifestation is not easy to know. Diagnosis established from symptom of upper and lower GI tract, from faecal calprotectin >2.100 ug/g, from colonoscopy and EGD revealed multiple ulcus colon with skip lesions, pangastritis superficialis, from histopathology revealed active chronic gastritis and colitis and extraintestinal manifestation (secondary ammenorhea).