Very-early-onset inflammatory bowel disease versus late-onset inflammatory bowel disease in relation to clinical phenotype: A cross-sectional study.

Background: Inflammatory bowel disease (IBD) is a chronic condition and children are affected by the disease's burden and therapeutic interventions for much longer than adults. Children of various ages can be diagnosed with IBD.

Methods: The research was carried out at the Pediatric Gastroenterology Clinic at Cairo University's Faculty of Medicine's Children's Hospital. From January 2013 to December 2017, this single-center observational cross-sectional study included 197 children aged 14 years and compared the clinical phenotypes of very-early-onset IBD (VEO-IBD) in patients aged six years and late-onset IBD (LO-IBD) in patients aged six to 14 years.

Results: Children with IBD at less than six years of age have a more colonic phenotype than children diagnosed later in life, who are more likely to have ileocolonic diseases (p = 0.002). In VEO-disease Crohn's (VEO-CD), growth failure/poor weight gain was 14%, while in LO-CD, it was 31%. Children with VEO-IBD do not always present with more severe disease than older children. Most clinical features in children with VEO-ulcerative colitis (VEO-UC) and LO-UC were similar at the first presentation, with the exception of abdominal pain, which was significantly less common in the VEO-UC group (p = 0.001) and hematochezia, which was significantly more common in the LO-UC group (p = 0.048). Children with VEO-disease Crohn's (VEO-CD) had a higher risk of bloody stools, diarrhea and fever (p = 0.013, p = 0.001 and p = 0.008, respectively), but a lower risk of abdominal pain (p = 0.000).

Conclusions: Growth failure/poor weight gain occurred in 14% of VEO-CD patients and 31% of LO-CD patients. In LO-UC, abdominal pain and hematochezia were significantly more common. In LO-CD, hematochezia, diarrhea and fever were significantly more common. In LO-IBD-U, abdominal pain and diarrhea were significantly more common.