East End Gastroentrology & Hepatology
We are proud to announce video visits are available now, click the link below or call the office today to request an appointment!
Call Us: 631-591-3000


Mark J. Coronel, MD - Riverhead, Manorville, NYMark J. Coronel, MD


LICENSURE:Diplomate, American Board of Gatroenterology; Diplomate, American Board of Internal Medicine

FELLOWSHIP TRAINING: North Shore LIJ Health System, Chief Fellow

INTERNSHIP & RESIDENCY: Internal Medicine, Albert Einstein College of Medicine, Long Island Jewish Medical Center, New Hyde Park, NY

MD: Albert Einstein College of Medicine, Bronx, NY

BA: Biology (magna cum laude), Yeshiva University

MEMBER: American College of Gastroenterology, American Society of Gastrointestinal Endoscopy, American Gastroenterological Association

Dr. Coronel graduated magna cum laude from Yeshiva University with a BA degree in biology. Subsequently, he received his MD from Albert Einstein College of Medicine in Bronx, NY. He did his internship and residency training in internal medicine at the Albert Einstein program, Long Island Jewish Medical Center in New Hyde Park, followed by gastroenterology and hepatology training in the North Shore-Long Island Jewish health system and a transplant hepatology rotation at Montefiore Medical Center.

Dr. Coronel has been involved for several years in clinical research in gastroenterology and hepatology. He has authored and presented several abstracts, posters and oral presentations at national meetings. In 2006, he was honored by the American College of Gastroenterology with the Governors Award for Excellence in Clinical Research and Best Scientific Paper. In 2010, He was invited into the Curatio National Inflammatory Bowel Disease mentorship program.

Dr. Coronel is an attending physician at Peconic Bay Medical Center. where he currently serves as director of endoscopy for the hospital. He is also actively involved in teaching medical students, interns and residents in family medicine and surgery. His primary interests include colon cancer screening, pancreatic disease, gastroesophageal reflux (GERD) management, inflammatory bowel disease and biliary tract disease using ERCP, capsule endoscopy and small bowel enteroscopy procedures.

Kim RiegelYKimberly Riegel, FNP-BC


Kimberly Riegel, FNP-BC, is a family nurse practitioner who specializes in Gastroenterology. Kimberly completed her Bachelor of Science in Nursing at Molloy College, New York, and earned her Master of Science degree at Stony Brook University in New York. She holds a national certification with the American Academy of Nurse Practitioners. Kimberly brings with her 13 years of GI experience in treating patients for a variety of conditions, including abdominal pain, diarrhea, acid reflux disease, gastrointestinal bleeding, inflammatory bowel disease, colon cancer screening, and more.

Gastroenterology services are in high demand, and we are grateful to be able to add another provider to our mix to help meet the needs of our patients and community.

Call East End Gastroenterology and Hepatology today to schedule!

Find a caring, attentive doctor at East End Gastroenterology & Hepatology. Call 631-591-3000. Or use our convenient Request an Appointment form. Dr. Coronel welcomes patients from Manorville, Mastic, Riverhead, Patchogue, East End and nearby areas.

Locate Us

Riverhead Office

715 Roanoke ave, Building B, Riverhead, NY 11901

Manorville Office & Endoscopy Center

287 Wading River Road Unit 2 Manorville, NY 11949