I am Carlos San Mateo, MD, MA, FACS, DABS, FASCRS, a board-certified colorectal and general surgeon with over a decade of experience in advanced anorectal procedures, cancer prevention, and integrative wellness. As Founder and President of Alkimiya Surgical Systems, PC and Director of the Anal Dysplasia Clinic at Kaiser Permanente–San Francisco, my practice is deeply committed to equitable, affirming, and inclusive care for LGBTQ+ communities, particularly those at higher risk for anal cancer and HPV-related disease.

My clinical expertise centers on high resolution anoscopy (HRA), a critical screening and surveillance tool for HPV-related anal dysplasia and anal cancer, conditions that disproportionately affect LGBTQ+ patients, especially men who have sex with men, transgender women, and individuals living with HIV. I have led regional initiatives within Kaiser Permanente to develop and implement anal dysplasia screening guidelines aligned with the International Anal Neoplasia Society, ensuring that LGBTQ+ patients receive evidence-based, culturally competent care.

Beyond clinical practice, I have a long-standing commitment to LGBTQ+ advocacy and education. During my training, I served on the Massachusetts Medical Society Special Committee on LGBT Matters (2008–2009), contributing to policy discussions on equitable healthcare access. I am an active member of the International Anal Neoplasia Society (since 2019), which advances research and education in anal cancer prevention for LGBTQ+ populations. My teaching roles—including mentorship of nurse practitioners in HRA and lectures for surgical residents and fellows—emphasize inclusive language, trauma-informed care, and sensitivity to LGBTQ+ identities in clinical settings.

I provide comprehensive colorectal and anorectal care that integrates both surgical and non-surgical approaches, including hemorrhoid management, fissure treatment, fistula repair, and minimally invasive cancer surgery. My philosophy of care is rooted in affirmation, dignity, and patient empowerment, ensuring that LGBTQ+ patients feel safe, respected, and fully informed in their healthcare decisions.

In addition to my surgical practice, I am passionate about integrative wellness and preventive medicine, reflected in my leadership at Alkimiya Surgical Systems. Our mission is to create print-ready educational resources, compliance guides, and enrichment tools that empower patients and staff alike. This includes LGBTQ+-specific cancer screening guides, decision matrices for preventive care, and lifestyle medicine enrichment resources that address the whole person.