Does ulcerative colitis lead to toxic megacolon in children?

Yes. Yes uc can cause toxic megacolon. This is best looked for with a simple abdominal xray. Typically patients look quite ill when they have toxic megacolon. It is definitely an emergency and would need to be managed in the hospital urgently.
Toxic megacolon i. In pediatric age group including infancy toxic megacolon has been reported as a complication of ulcerative colitis.It used to be anywhere between 1 to 5 percent in the seventies but the incidence has gone down, due to early diagnosis and improved management of ulcerative colitis in pediatric age group and even if it happens the prognosis with early diagnosis and management has improved.