Inclusion Criteria:
1. Diagnosis of any type of genitourinary (kidney, bladder and prostate), melanoma, non-melanoma skin cancer, lung, head \& neck, sarcoma/lymphoma, gastrointestinal system (luminal GI, hepatobiliary, pancreas), gynecology system (ovarian, uterine, cervical), and breast malignancies
2. Treatment with any ICPI agent(s)
3. Participants with new onset of ≥ grade 2 ICPI-induced diarrhea and/or colitis symptoms based on the Common Terminology Criteria for Adverse Events (CTCAE) version 5 within 45 days prior to date of FMT treatment without involvement of non- GI toxicity
4. Participants with a history of steroid use before FMT can be allowed if last dose was \> 30 days prior to FMT treatment or treatment duration was for \<7 days beyond one week prior to FMT treatment
5. Participants with a history of immunosuppressant (Infliximab, Vedolizumab etc) use before FMT can be allowed if last dose was administered ≥ 3 months prior to FMT treatment when used for the treatment of conditions other than for ICI- induced GI toxicities (e.g., Infliximab is used in the treatment of Crohn's disease, rheumatoid arthritis, plaque psoriasis, and Vedolizumab is used in treating ulcerative colitis)
6. No concern for active concomitant GI infection at the time of initiation of protocol therapy as confirmed by stool tests or as per the treating physician based on clinical presentation
7. Patient has been cleared for enrollment by Infectious Diseases consultant or treating physician if positive infection workup or screening tests (e.g., lifelong positive T-spot due to BCG inoculation, chronic colonization) prior to initiation of protocol therapy and/ or imaging (e.g. CXR, CT CAP etc) confirms the absence of active infections (e.g. TB) within 60 days prior to initiation of protocol therapy
8. Ability to understand and willingness to sign an informed consent form
9. Life expectancy \> 6 months
Exclusion Criteria
1. Age younger than 18 years
2. Participants with persistent GI infection confirmed with positive stool test(s) despite completing 5 days of antibiotics prior to initiation of protocol therapy
3. History of inflammatory bowel disease, and/or radiation enteritis or colitis with active disease status at the time of study treatment initiation
4. Pregnant and breastfeeding women
5. Women who have positive urine or serum pregnancy test or refuse to do pregnancy test unless last menstrual cycle was \> 1 year prior to consent and/ or clear documentation states that participant is peri- or post-menopausal or there has been recent supporting objective evidence of 'no pregnancy' status (e.g. blood or imaging) within 30 days prior to date of study treatment
6. Immunosuppressive treatment at onset of ICPI-induced diarrhea/colitis
7. Any medical conditions (e.g. severe heart failure, brain hemorrhage, septic shock, etc.) that are high risk for colonoscopy procedure by the assessment of the study PI or Co-PIs.
8. Participants who develop concurrent non-GI toxicity at the time of study treatment
9. Donors at risk for monkeypox infection and/ or exposure as determined by a questionnaire
