This study is exploring how well a drug called guselkumab works for kids with Crohn's Disease (CD). Crohn's Disease is a condition where your digestive tract becomes inflamed, which can cause belly pain, diarrhea, and tiredness. The study will last for 52 weeks (about a year). To join, kids need to already have moderate to severe CD and have shown some improvement with guselkumab by Week 12. An endoscopy is a test where doctors look inside your body to check for inflammation. Kids who haven't responded well to other treatments or had trouble with them might be a good fit for this study.

• The study lasts about a year, with regular visits to the doctor.
• Kids already needing surgery or with certain complications cannot join.
• Participation might involve risks, but it could help improve CD symptoms.