Evaluation of the characteristics of childhood inflammatory bowel diseases according to disease groups and the age at symptom onset

Inflammatory bowel disease (IBD) is a group of multisystemic diseases characterized by multifactorial chronic idiopathic intestinal inflammation. Inflammatory bowel disease encompasses the diagnoses which include Crohn's disease, ulcerative colitis and unclassified colitis. It is also classified according to age groups and disease characteristics change between different age groups. This study included 92 patients who were diagnosed with IBD between 2000-2017 in the Department of Child Gastroenterology, Hepatology and Nutrition, Hacettepe University. Patients were divided into groups according to the diagnosis of ulcerative colitis or Crohn's disease and the age at symptom onset before or after 6 years of age. The patient who's age at symptom onset is before 6 years, defined as very early onset IBD. 57 patients (61,9%) were diagnosed with Crohn's disease, 33 (35,8%) with ulcerative colitis and 2 (2,2%) unclassified colitis. The mean age at symptom onset was earlier in Crohn's disease than in ulcerative colitis (6,95,6 years/9,65 years). The time between symptom onset and diagnosis was longer in Crohn's disease than in ulcerative colitis (1,42,0 years/1,11,9 years). Abdominal pain and diarrhea were the most common symptoms in Crohn's disease while bloody stool was in ulcerative colitis. Occult blood in stool, anemia and elevated C-reactive protein levels were the most common laboratory results. Erythrocyte sedimentation rate and C-reactive protein level were higher in Crohn's disease. Acute phase reactants were within normal limits in 18 (19,6%) patients. The most abnormal finding was detected on gastric mucosa in esophagogastroduodenoscopy. All patients with ulcerative colitis had abnormal colonoscopy findings and pancolitis was the most common finding (54,5%). "Backwash ileitis" was detected in 5 (15,1%) patients. Ileocolonic involvement was the most common finding (45,6%) in Crohn's disease. Seven patients had terminal ileum involvement while colon was normal. The most common abnormal finding in histopathological evaluation was active colitis. Corticosteroids, 5-aminosalicylate and azathiopurine were used mostly as therapeutic agents whereas 10 patients treated with anti-TNF drugs. Immunodeficiency was detected in 20 of the 48 patients (41,7%) who underwent immunologic evaluation and 4 of them underwent stem cell transplantation. Two of them had reached clinical remission after stem cell transplantation and all treatment was with-drawn. There were 36 patients (39,1%) who were under 6 years of age at symptom onset. In which Crohn disease was much more common (%75,0/%53,6) and the mean time between symptom onset and diagnosis was longer (2,0 ± 2,7 years/0,91,0 years). The most common complaint was diarrhea (80,6%) in very early onset IBD patients whereas it was abdominal pain (87,5%) in the older onset group. Isolated upper gastrointestinal system involvement in Crohn's disease was not seen in very early onset IBD patients. Ulcerative colitis mostly gone with pancolitis in both ages and no proctitis or left colon involvement was seen in very early onset group. Growth retardation and refractory disease were more common in very early onset group. Key words: Inflammatory bowel disease, very early onset inflammatory bowel disease, Ulcerative colitis, Crohn's disease