Chronotherapy of 5-Aminosalicylic Acid in Ulcerative Colitis

The hypothesis of this study is that appropriate time of day of administration of oral, once daily 5-ASA therapy in alignment with the host circadian rhythms will improve subclinical inflammation and microbial structure/function and increase mucosal 5-ASA levels. All subjects will be randomized to once daily 5-ASA medications at two different times of the day: between 06:00 - 10:00 h or 18:00 - 22:00 h. Three disease assessments will performed at: 1) enrollment just before randomization; 2) month 3, at the completion of first arm (Condition 1), and 3) month 6, after completion of the second arm (Condition 2). During these study time points, participants will be asked to complete questionnaires, track their 5-ASA medication usage, provide a stool sample, blood draw, urine test, wear a watch to measure sleep patterns, and complete a flexible sigmoidoscopy.