Personalized B-fructan Diet in Inflammatory Bowel Disease Patients

This study is exploring how a personalized diet high in a type of fiber called B-fructans affects gut bacteria and inflammation in children and young adults with inflammatory bowel disease (IBD), including ulcerative colitis. **You may be eligible if...** - You are between 6 and 39 years old - You have known or suspected ulcerative colitis or unclassified IBD with mild to moderate disease activity - Your disease treatment has been stable (no steroids, no recent changes to biologics or immune-modifying drugs) - You are scheduled for a sedated colonoscopy - You are likely able to collect all required samples **You may NOT be eligible if...** - You have taken antibiotics for a week or more in the past 3 months - You have had abdominal surgery (including appendix removal) - You have had a bowel infection in the past 3 months - You have only rectal (proctitis) involvement - You are currently on high-dose steroids - You are pregnant or planning to become pregnant - You have a serious illness unrelated to IBD (such as cancer or kidney failure) Talk to your doctor to see if this trial is right for you.