This is a longitudinal, observational study that aims to identify the microbial and human molecular triggers of IBD flares via stool, saliva, and blood metatranscriptomes, whole blood proteome, and collected clinical metadata. This study is direct to participant and will not utilize clinical sites.

This is a longitudinal, observational study that aims to identify the microbial and human molecular triggers of IBD flares via stool, saliva, and blood metatranscriptomes, whole blood proteome, and collected clinical metadata. This study will last approximately 3 years and will recruit up to 1000 Crohn's Disease participants and up to 1000 Ulcerative Colitis participants that will participant in the study for approximately 12 months. Participants will be sent at home sample collection kits and a study survey each month. If the survey responses indicate a participant is in a flare, they will be sent a sample collection kit and survey on a weekly basis until the flare is over and the monthly schedule resumes. The objective of the data analysis is to identify microbial functions that are predictive of the onset of a flare.

Inclusion Criteria:

• 18 years of age or older
• Able to provide written informed consent prior to screening
• Established diagnosis of small bowel or colonic Crohn's Disease (CD) or Ulcerative Colitis (UC)

Exclusion Criteria:

• Pregnant or breastfeeding
• Use of antibiotics within the last 3 months
• Bowel surgery in the past 3 months or planned bowel surgery during the 12-month study period

The study population will be composed of up to 1000 Ulcerative Colitis participants and up to 1000 Crohn's Disease participants that are 18 years of age or older and that meet the inclusion criteria.