Natural History of Pediatric-onset Inflammatory Bowel Disease A Systematic Review

Background/Aims: There has been no systematic review of natural history studies of pediatric-onset inflammatory bowel disease (IBD). We conducted a systematic review focused on understanding the long-term risks of growth failure, disease reclassification and extension, hospitalizations, cancer and death among patients with childhood IBD. Methods: PubMed searches and subsequent data abstraction were performed by 2 independent investigators. Studies published full in english with a 5-year minimum average follow-up in at least 30 patients with IBD onset before age 18 years. Results: We evaluated 41 total studies (only 2 population-based studies) with 3505 Crohn's disease (CD) patients, 2071 ulcerative colitis (UC) patients, and 461 indeterminate colitis (IC). Growth failure was reported in CD (10% and 56%) more often than UC (0% to 10%) or non-IBD controls. Improvements in growth occurred after surgical resection in patients with CD. There was an increase in disease reclassification over time from UC and indeterminate colitis diagnosis to CD diagnosis. Patients with CD had higher number of hospitalizations and hospital days per year in comparison with UC patients in most studies. The reported surgery rates in CD ranged between 10% and 72%; the colectomy rates in UC ranged between 0% and 50%. Cancers were reported in 6 CD patients during a total 18,270 patient-years (PY) follow-up, and 8 UC patients in 18,115 PY. Deaths directly related to IBD were 63 during 39,719 PY. Conclusions: Childhood-onset IBD patients had growth failure reported in patients with CD more often than those with UC, had a reclassification of disease type to CD over time. Higher rates of surgery and hospitalizations were found with CD than with UC. The risk of cancer and death is low in this population.