Resistant Starch in Pediatric Inflammatory Bowel Disease (Crohn's Disease or Ulcerative Colitis)

Inclusion Criteria: * Capable of giving informed consent, or if appropriate, have an acceptable representative capable of giving consent on the participant's behalf. * Enrolled in the main parent study. * New ulcerative colitis diagnosis (mild/moderate) or Crohn's Disease diagnosis (moderate/severe) with colonic disease with or without terminal ileum disease, already started on oral corticosteroid or aminosalicylates for induction therapy at a time following diagnostic colonoscopy. * Clinically responsive to induction medical therapy at enrollment (Crohn's Disease participants with a weighted pediatric Crohn's Disease activity index decrease of ≥ 17.5 points or ulcerative colitis participants with a pediatric ulcerative colitis activity index decrease of ≥ 15 points). * Ability and willingness to comply with study procedures (e.g. stool collections) for the entire length of the study. * Willing to provide consent/assent for the collection of stool samples. Exclusion Criteria: * Allergy to resistant starch or excipients. * Co-existing diagnosis with diabetes mellitus. * Treatment with another investigational drug or intervention throughout the study. * Current drug or alcohol dependence that, in the opinion of the site investigator, would interfere with adherence to study requirements. * Inability or unwillingness of an individual or legal guardian to give written informed consent. * Requirement for antibiotic therapy as part of standard Crohn's Disease therapy (i.e. those …