• Informed consent will be obtained before any study-related procedures

• Age \>/= 18 and \</= 80 years

• Diagnosis of Chronic Pouchitis or Crohn's-like disease of the pouch based on the following criteria:

‣ Chronic Antibiotic-Dependent Pouchitis: Recurrent symptoms of pouchitis (frequency, urgency, bleeding, abdominal pain or cramping, or pelvic discomfort) that respond to antibiotic therapy but relapse shortly after stopping antibiotics, thus necessitating continuous antibiotic therapy to achieve symptom control.

⁃ Chronic Antibiotic Refractory Pouchitis: Lack of response to standard antibiotic therapy, requirement of a longer duration of antibiotic therapy than expected with minimal improvement in symptoms, in association with typical symptoms of pouchitis (frequency, urgency, bleeding, abdominal pain or cramping, or pelvic discomfort).

⁃ Crohn's-like disease of the pouch: Presence of a perianal or other fistula that developed at least 12 months after the final stage of Ileal Pouch Anal Anastomosis (IPAA) surgery, stricture of the pouch body or pre-pouch ileum, or the presence of pre-pouch ileitis. Pouch body inflammation (pouchitis) may often coexist in the setting of Crohn's-like disease of the pouch.

• Participants with a proven history of ulcerative colitis and history of 1,2, modified -2 or 3 stage IPAA and ileostomy takedown

• Ability to access internet for electronic database entry

• Only those individuals for whom a provider is considering initiating mirikizumab for the treatment of chronic pouchitis or Crohn's-like disease of the pouch will be eligible for participation.