Ulcerative colitis is a chronic inflammatory disease primarily involving the colon and has long been considered to be due to a dysregulated immune response targeting the colon, and involves unknown environmental factors. Currently, no effective therapy targets the microbiota or its interaction with the colonic epithelium. Diet has a significant impact on the composition of the microbiota; however, no dietary intervention to date has proven effective for induction of remission. The primary objective of this study is to determine whether the Ulcerative Colitis Diet (UCD) can induce remission or response in pediatric UC patients with active mild to moderate UC on a stable medication.

Inclusion Criteria:

• Informed consent
• Established diagnosis of UC
• Age: 8-19 (inclusive)
• Mild to moderate active disease, 10<PUCAI<45
• Stable medication (IMM/5ASA) use or no medication use for the past 6 weeks.
• Participant has agreed to follow the UCD for 12 weeks

Exclusion Criteria:

• Any proven current infection such as positive stool culture, parasite or C. difficile within the past 4 weeks
• Antibiotic or corticosteroid use in the past 2 weeks
• Use of biologics in present or in the past
• PUCAI>45
• Acute severe UC in the previous 12 months
• Current extra intestinal manifestation of UC
• Primary Sclerosing Cholangitis (PSC) or liver disease
• Pregnancy
• Known food allergy to mandatory foods in the UCD