About Us

Joseph Mareno, Jr, MD, FACS, FASCRS

Dr. Joseph A. Mareno, Jr. is a board-certified colorectal surgeon who was raised in East Cobb, Georgia. He graduated magna cum laude from Berry College in 1999 and Emory University School of Medicine in 2003. He completed his general surgery residency at the University of California San Diego Medical Center. There, he was the recipient of the Halasz “Golden Flea” Award for Excellence in Surgical Consultation. Dr. Mareno completed his fellowship in Colon & Rectal Surgery at the Cleveland Clinic in Florida.

Dr. Mareno practices all aspects of colon and rectal surgery including treatment of Crohn’s disease, ulcerative colitis, colon and rectal cancer, diverticulitis, hemorrhoids, anal fissures, pelvic floor disorders, and fecal incontinence. He has advanced training in minimally invasive surgery, including laparoscopy, transanal endoscopic microsurgery (TEMS), and transanal minimally invasive surgery (TAMIS). Dr. Mareno is a certified member of the MD Anderson Cancer Network, a Fellow of the American College of Surgeons and a Fellow of the American Society of Colon and Rectal Surgeons.  He serves on the Perioperative Governance Committee and Leadership Council of Piedmont Atlanta Hospital. He received the Patients’ Choice Award in 2014 and was named to Atlanta magazine’s Top Doctors list in 2015, 2016, and 2017.

Evan Feldman, MD, FACS, FASCRS

Dr. Evan Feldman is a board-certified colorectal surgeon who practices all aspects of colon and rectal surgery. He earned his bachelor’s degree from Brown University in Providence, Rhode Island, where he studied public health and graduated with honors. He received his medical degree from Emory University, where he graduated with honors and was a member of the Alpha Omega Alpha Honor Medical Society. He completed his surgical internship and residency at New York Presbyterian Hospital/Weill-Cornell Medical Center and Memorial Sloan-Kettering Cancer Center in New York City. He completed his fellowship in colon and rectal surgery at Barnes-Jewish Hospital/Washington University School of Medicine in St. Louis, Missouri.

Dr. Feldman is the service chair for colorectal surgery at Piedmont Atlanta Hospital, the medical director of the Colorectal Multidisciplinary Tumor Board for the Piedmont Healthcare System, and serves in leadership positions on several other hospital and system-wide committees. In 2017, he received the Piedmont Clinic Chairman’s Service Award recognizing his work reducing colorectal surgery infections across the Piedmont Healthcare system. In 2018, he received the William C. Waters Award for Clinical Excellence, chosen by the Piedmont Medical Staff for superior patient care and leadership. Dr. Feldman is also an adjunct Clinical Assistant Professor at Mercer Health Sciences Center. He is a Fellow of the American College of Surgeons, and a Fellow of the American Society of Colon and Rectal Surgeons. He has advanced training in colonoscopy and minimally invasive surgery, including laparoscopy, robotic-assisted surgery, transanal endoscopic microsurgery (TEMS) and transanal minimally invasive surgery (TAMIS).

Dr. Evan Feldman has been named a TOP DOCTOR by Castle Connolly and Atlanta Magazine in 2019, 2020, 2021, and 2022.

Swetha Ramakrishnan, MD, FACS, FASCRS

Dr. Swetha Ramakrishnan is a board-certified colorectal surgeon who grew up in North Brunswick, New Jersey. She graduated with the highest distinction from a combined 7 year BS/MD program from Pennsylvania State University with a degree in life science and a minor in German language. She received her MD degree from Jefferson Medical College where she was inducted into the Alpha Omega Alpha Honor Medical Society. She then completed her general surgery residency at the Emory University School of Medicine, where she also completed a 2-year post-doctoral research fellowship in transplant immunology. She completed her fellowship in colon and rectal surgery at Barnes-Jewish Hospital/Washington University School of Medicine in St. Louis, Missouri.

Dr. Ramakrishnan is a Fellow of the American College of Surgeons and a Fellow of the American Society of Colon and Rectal Surgeons. She treats all colon and rectal conditions including colon cancer, anal cancer, inflammatory bowel disease, diverticulitis, hemorrhoids, fissures, fistulae, abscesses, and pilonidal disease. She has a particular interest in the diagnosis and treatment of pelvic floor disorders including fecal incontinence, constipation, levator syndrome, and post-partum anorectal disease. In addition to colonoscopy, laparoscopy, and transanal minimally invasive surgery (TAMIS), she performs sacral neuromodulation (SNS) for fecal incontinence, in-office anorectal manometry, and the Cleft Lift procedure for pilonidal disease. Dr. Ramakrishnan also leads the anal cancer prevention program and completed the ASCCP course on HPV related genital tract disorders and High Resolution Anoscopy (HRA) in 2017. She performs in-office HRA to detect and treat high grade dysplasia, a known risk for development of squamous cell cancer of the anus and cervix. Dr. Ramakrishnan is currently the chairwoman of the Piedmont Atlanta Hospital Ethics Committee and serves as an adjunct clinical faculty member for Mercer University’s College of Health Professions. Dr. Ramakrishnan was named a Top Doctor by Atlanta Magazine and Georgia Trend Magazine in 2022.

Marissa Anderson, MD, FACS

Dr. Marissa Anderson is a board-certified surgeon who completed Colon & Rectal surgery fellowship at New York University Langone Health. Dr. Anderson received her undergraduate degree at Emory University in 2005 and graduated from the University of Miami Miller School of Medicine in 2010 where she was a member of the Alpha Omega Alpha honor society. She completed her general surgery residency at the University of Texas Southwestern in Dallas in 2015, after which she was in practice in Boston for 3 years as teaching faculty in General Surgery at Cambridge Health Alliance/Harvard Medical School prior to pursuing fellowship training.

Dr. Anderson has advanced training in colonoscopy and minimally invasive surgery, including robotics, laparoscopy and transanal minimally invasive surgery (TAMIS). Her fellowship provided her with extensive training in robotic-assisted surgery and operations for inflammatory bowel disease and her particular interest is in the application of the robot for complex surgery, particularly inflammatory bowel disease and colorectal cancers. She is also a certified member of the American Board of Colorectal Surgery.

Monica Hum, MD, MBA, FACS, FASCRS – Partner Emeritus


Dr. Monica Hum is a board-certified colorectal surgeon who started practicing at Piedmont Hospital in 2003 and founded ATL Colorectal Surgery, PC in 2007. She retired from clinical practice in 2021 to join the Piedmont Healthcare System as Chief Medical Officer of Piedmont Rockdale Hospital.

Dr. Joseph Mareno

Dr. Evan Feldman

Dr. Swetha Ramakrishnan

Dr. Marissa Anderson