Inclusion Criteria:  In order to be eligible to participate in this study, an individual must meet all of the following criteria:  Subjects > 18 years and < 80 years of age a confirmed diagnosis of IBD or > 6 months post- RYGB, with a diagnosis USD event (renal colic with spontaneous stone passage, emergency room visits, or urological interventions) or have kidney stone on imaging (CT, MRI, or US) in the previous three years. We will include all racial and ethnic groups, and both men and women.  In order to be eligible in this study as a healthy control, an individual must meet all of the following criteria:  Subjects > 18 years and < 80 years of age Healthy controls with no chronic diseases, not on any chronic medications, no history of GI pathology, or urinary stone disease (USD). We will include all racial and ethnic groups, and both men and women.  Exclusion Criteria:  An individual who meets any of the following criteria will be excluded from participation in this study:  pregnant or nursing women and people with any medical, psychiatric, debilitating disease/disorder or social condition that, in the judgment of the investigator, would interfere with or serve as a contraindication to adherence to the study protocol, ability to give ICF or complete the protocol. subjects with total and partial colectomy. subjects who received oral, intramuscular, or intravenous antibiotics within three months before screening. Patients with perianal disease usually receive recurrent antibiotics and, therefore, will be excluded from the study. patients with an ongoing symptomatic IBD flare or a flare within the previous three months patients with estimated glomerular filtration rates (eGFR) < 60 ml/min/1.73 m2 calculated by the CKD-EPI equation measured anytime within the preceding year.  An individual who meets any of the following criteria will be excluded from participation in this study as a healthy control:  pregnant or nursing women and people with any medical, psychiatric, debilitating disease/disorder or social condition that, in the judgment of the investigator, would interfere with or serve as a contraindication to adherence to the study protocol, ability to give ICF or complete the protocol. subjects with total and partial colectomy. subjects who received oral, intramuscular, or intravenous antibiotics within three months before screening. Patients with perianal disease usually receive recurrent antibiotics and, therefore, will be excluded from the study. patients with an ongoing symptomatic IBD flare or a flare within the previous three months patients with estimated glomerular filtration rates (eGFR) < 60 ml/min/1.73 m2 calculated by the CKD-EPI equation measured anytime within the preceding year.