Patients who are scheduled for a colonoscopy at the Vanderbilt Endoscopy Laboratory as part of their routine care and who do not meet any of the pre-defined exclusion criteria will be considered for participation in the study as control subjects. Patients who are part of the Vanderbilt IBD practice who initiate therapy on an anti-TNF or ustekinumab as part of their routine care will be considered for participation in the study as subjects.