David M. Parker, MD, FACS, FASMBS, is a board-certified general surgeon specializing in bariatric surgery for both adolescents and adults. Dr. Parker performs several advanced and specialized surgical procedures, including gastric bypass, biliopancreatic diversion with duodenal switch, revisional bariatric surgery, laparoscopic gastric band (or “lap band”) and gastric sleeve. He also provides care for various conditions affecting the stomach and gastrointestinal (GI) system, including hiatal hernia, paraesophageal hernia, achalasia and acid reflux.|He has a clinical interest in minimally invasive laparoscopic and robotic surgery.|Board-certified in general surgery, Dr. Parker earned his medical degree from West Virginia University in Morgantown. He completed a general surgery residency at the Dwight D. Eisenhower Army Medical Center in Fort Gordon, GA, followed by a fellowship in bariatric and foregut surgery at Geisinger Medical Center in Danville.|While in medical school, he received the Presidential Award for Excellence in Scholarship. During his fellowship, he received the SAGES Award for best fellow presentation.|Dr. Parker serves as program director for the Geisinger bariatric and foregut surgical fellowship. He has a strong commitment to research in bariatric and foregut surgery and has authored more than 24 published articles.|He is an active member of the Society of Gastrointestinal and Endoscopic Surgeons and a fellow of the American College of Surgeons and American Society of Metabolic and Bariatric Surgeons.|Dr. Parker has served in the United States Army and continues to serve as a lieutenant colonel in the United States Army Reserve. He is also a football enthusiast, rooting for the West Virginia Mountaineers in his free time. Dr. Parker is rated as an Elite provider by MediFind in the treatment of Hernia. His top areas of expertise are Hiatal Hernia, Hernia, Obesity, Gastric Bypass, and Endoscopy.

Jon Gabrielsen is a General Surgeon in Lewisburg, Pennsylvania. Dr. Gabrielsen is rated as a Distinguished provider by MediFind in the treatment of Hernia. His top areas of expertise are Hiatal Hernia, Hernia, Achalasia, Gastric Bypass, and Gallbladder Removal.

Anthony T. Petrick, MD, FACS, FASMBS, is a board-certified general surgeon specializing in esophageal and bariatric surgery. Dr. Petrick performs a number of advanced and specialized surgical procedures including advanced endoscopy, revisional bariatric surgery, laparoscopic gastric band (or “lap band”), gastric bypass, biliopancreatic diversion with duodenal switch and gastric sleeve. He also treats people for various conditions affecting the stomach and gastrointestinal (GI) system, including hiatal and paraesophageal hernia, achalasia and acid reflux (GERD).|Board-certified in general surgery, Dr. Petrick earned his medical degree from Georgetown University in Washington, D.C. He completed general surgery residency at Georgetown University Medical Center in Washington, D.C. He then completed a fellowships in Surgical Oncology at and Beth Israel Deaconess Medical Center in Boston and in Bariatric and Foregut surgery at the University of Pittsburgh Medical Center.|For the past 18 years, Dr. Petrick served as program director for the Geisinger bariatric and foregut surgical fellowship. He now serves as associate program director, acting as a mentor to bariatric surgery fellows. Dr. Petrick has a strong commitment to research in bariatric and foregut surgery and has authored more than 100 articles. Currently, he serves as chief quality officer for inpatient services at Geisinger and Director of the Division of Bariatric and Foregut surgery.|Dr. Petrick is an active member of the Society of Gastrointestinal and Endoscopic Surgeons and a fellow of the American College of Surgeons and American Society of Metabolic and Bariatric Surgeons. He chairs to Data and Quality Committee for the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program and also serves as an editorial board member for the journal Surgical and Obesity-Related Diseases and a columnist for Bariatric Times.|In his free time, Dr. Petrick serves on the board of education at St. Joseph School in Danville. He also coaches the Susquehanna Valley Stampede varsity and junior varsity ice hockey teams.|Clinical Focus: Bariatric Surgery|If you’re a provider who’d like to refer a patient, call our 24/7 referral line at 800-332-8901 or visit www.emr-link.com. Dr. Petrick is rated as a Distinguished provider by MediFind in the treatment of Hernia. His top areas of expertise are Obesity, Hiatal Hernia, Hernia, Gastric Bypass, and Endoscopy.

Christopher Motto is a General Surgeon and a Bariatric Medicine provider in Lewisburg, Pennsylvania. Dr. Motto is rated as an Advanced provider by MediFind in the treatment of Hernia. His top areas of expertise are Familial Colorectal Cancer, Hernia, Gallbladder Disease, Hernia Surgery, and Pacemaker Implantation.

Gary Ayers is a General Surgeon and an Undersea and Hyperbaric Medicine provider in Lewisburg, Pennsylvania. Dr. Ayers is rated as an Advanced provider by MediFind in the treatment of Hernia. His top areas of expertise are Familial Colorectal Cancer, Gallbladder Disease, Gallstones, Pacemaker Implantation, and Hernia Surgery.

Joseph Mucciolo is a General Surgeon in Lewisburg, Pennsylvania. Dr. Mucciolo is rated as an Advanced provider by MediFind in the treatment of Hernia. His top areas of expertise are Hernia, Umbilical Hernia, Gallbladder Disease, Bladder Reconstruction, and Colostomy.

Daria Keyser is a General Surgeon in Lewisburg, Pennsylvania. Dr. Keyser is rated as an Experienced provider by MediFind in the treatment of Hernia. Her top areas of expertise are Ogilvie Syndrome, Gallbladder Disease, Gallstones, Hernia Surgery, and Pacemaker Implantation.

Aaron Feaster is a General Surgeon in Lewisburg, Pennsylvania. Dr. Feaster is rated as an Experienced provider by MediFind in the treatment of Hernia. His top areas of expertise are Ogilvie Syndrome, Retroperitoneal Inflammation, Cellulitis, Hernia Surgery, and Pacemaker Implantation.

Vladan Obradovic, MD, is a general surgeon specializing in bariatric surgery. Dr. Obradovic performs a number of advanced and specialized weight loss surgery procedures, including biliopancreatic diversion with duodenal switch, advanced endoscopy, revisional bariatric surgery, foregut surgery, laparoscopic gastric band (or “lap band”), gastric bypass and gastric sleeve.|Dr. Obradovic has a clinical interest in minimally invasive and robotic surgery.|Dr. Obradovic earned his medical degree from the University of Belgrade School of Medicine in Belgrade, Serbia. He completed residencies in general surgery at the Belgrade School of Medicine, and Health Centre Krusevac in Krusevac, Serbia, and digestive system and hepatobiliary surgery at the University Clinical Center of Belgrade. He then completed general surgery residency and fellowship in bariatric surgery at Geisinger Medical Center in Danville and a certification in robotic assisted surgery at Intuitive Surgical Headquarters in Sunnyvale, CA.|A resident of Danville, Dr. Obradovic is committed to serving his community by giving the best care he possibly can. He was inspired to pursue a career in medicine by his father, who was a physician.|In his spare time, he enjoys spending time with his family and friends and walking his dog. Dr. Obradovic is rated as an Advanced provider by MediFind in the treatment of Hernia. His top areas of expertise are Hiatal Hernia, Obesity, Hernia, Gastric Bypass, and Endoscopy.

Dr. Jaap is a board-certified general surgeon. She attended Wright State University, where she earned her medical degree. Dr. Jaap completed her residency at Geisinger Medical Center. She is certified by the American Board of Surgery. Dr. Jaap is rated as an Advanced provider by MediFind in the treatment of Hernia. Her top areas of expertise are Ogilvie Syndrome, Hernia, Juvenile Angiofibroma, Gallbladder Disease, and Hernia Surgery.

Matthew Souder, MD, is a board-certified general surgeon. He earned his medical degree from St. George’s University School of Medicine in Grenada. After medical school, he completed a residency in general surgery at PinnacleHealth in Harrisburg.|During his undergraduate training, Dr. Souder completed several research projects on fetal alcohol syndrome and other topics.|He’s a native of Lewisburg. Dr. Souder is rated as an Advanced provider by MediFind in the treatment of Hernia. His top areas of expertise are Juvenile Angiofibroma, Cellulitis, Gallstones, Choledocholithiasis, and Hernia Surgery.

As director of colorectal surgery, Chris Buzas, DO, specializes in treating patients with colon, rectal and anal cancers as well as inflammatory bowel disease (including Crohn’s disease and ulcerative colitis). He also provides care for people with diverticulitis, various rectal conditions, hemorrhoids and pelvic floor disorders.|He has clinical expertise in complex re-operative colorectal surgeries as well as robotic, laparoscopic and open procedures. His advanced training includes trans-anal excisions, neurostimulation for fecal incontinence and colonoscopies.|Dr. Buzas is passionate about making a difference in his patients’ lives. “The thing I love most about my job is the ability to work alongside a great team dedicated to solving problems,” he says. “I enjoy seeing our patients out in the community, knowing we were able to help improve their quality of life.”|Dr. Buzas has a strong commitment to giving back to his community and improving access to care. He previously served as president of the Keystone Chapter of the American College of Surgeons as well as on the Board of Trustees for the Pennsylvania Medical Society. Dr. Buzas has also helped standardize rectal cancer care throughout the country as part of the National Accreditation Program for Rectal Cancer.|Dr. Buzas received the Teacher of the Year Award from the surgical residents at Geisinger Medical Center. He was also recognized by the Pennsylvania Medical Society as one of their Top Physicians Under 40.|When not at work, Dr. Buzas enjoys spending time with his wife and three children at their lakeside cabin in northern Pennsylvania.|Video: more from Dr. Christopher Buzas, D.O. Dr. Buzas is rated as an Experienced provider by MediFind in the treatment of Hernia. His top areas of expertise are Familial Colorectal Cancer, Colorectal Cancer, Lynch Syndrome, Hernia Surgery, and Ileostomy.

Dr. Widom is a board-certified and fellowship-trained general surgeon subspecializing in trauma. His clinical interests include acute care surgery and emergency general surgery. Dr. Widom attended the University of Maryland, where he received his medical degree, and completed his residency at Robert Wood Johnson University Hospital. He completed his fellowship in surgical critical care at the University of Maryland. Dr. Widom is certified by the American Board of Surgery in surgical critical care. Dr. Widom is rated as an Experienced provider by MediFind in the treatment of Hernia. His top areas of expertise are Chronic Subdural Hematoma, Subdural Hematoma, Delirium, Small Bowel Resection, and Hernia Surgery.

Matthew Factor is a General Surgeon in Danville, Pennsylvania. Dr. Factor is rated as an Experienced provider by MediFind in the treatment of Hernia. His top areas of expertise are Chronic Subdural Hematoma, Subdural Hematoma, Delirium, Hip Replacement, and Gastrostomy.

Dr. Long is a board-certified and fellowship-trained colorectal surgeon. He obtained his medical degree from Virginia Commonwealth University and completed his residency at the same institute. Dr. Long completed his fellowship in colon and rectal surgery at Swedish Colon and Rectal Clinic. He is certified by the American Board of Colon and Rectal Surgery and the American Board of Surgery. Dr. Long is rated as an Experienced provider by MediFind in the treatment of Hernia. His top areas of expertise are Colorectal Cancer, Familial Colorectal Cancer, Crohn's Disease, Ileostomy, and Colostomy.

Dr. Foernges is a board-certified and fellowship-trained specialist in trauma critical care. His clinical interests include trauma surgery, gastrointestinal surgery and necrotizing soft tissue infection. Dr. Foernges graduated from Universidade Federal de Ciências da Saúde de Porto Alegre Faculdade de Medicina in Brazil, where he earned his medical degree. He completed his residency at Geisinger Medical Center, and his fellowship at MedStar Washington Hospital Center. Dr. Foernges is certified by the American Board of Surgery in surgical critical care. He speaks English, Portuguese and Spanish. Dr. Foernges is rated as an Experienced provider by MediFind in the treatment of Hernia. His top areas of expertise are Chronic Subdural Hematoma, Subdural Hematoma, Delirium, Hernia Surgery, and Hip Replacement.

Henry Yavorek is a General Surgeon in Selinsgrove, Pennsylvania. Dr. Yavorek is rated as an Experienced provider by MediFind in the treatment of Hernia. His top areas of expertise are Hernia, Diverticular Disease, Hiatal Hernia, Congenital Diaphragmatic Hernia, and Endoscopy.

Osama Shaheen, MD, is a general surgeon specializing in bariatric and foregut surgery. He performs a variety of surgical treatments for adults, including Nissen/Toupet fundoplication, Heller myotomy, laparoscopic hiatal hernia repair, LINX procedure, Roux-en-Y gastric bypass (RYGB), gastric sleeve, duodenal switch, single anastomosis duodeno–ileal bypass with sleeve gastrectomy, (SADI-S) and revisional bariatric surgery.|Dr. Shaheen attended Damascus University in Damascus, Syria, where he earned his medical degree. After medical school, he completed a residency at Damascus University Hospital. He followed that with a fellowship in multi-organ abdominal transplant surgery and a residency in general surgery, both at Thomas Jefferson University Hospital in Philadelphia. He also completed a fellowship in bariatric and advanced minimally invasive surgery with the Advanced Laparoscopic Surgery Associates (ALSA) Medical Group in Fresno, California.|He’s received several Excellence in Teaching Awards during his residency and fellowships.|He and his wife Latifa moved to the area in 2023. “I decided to move to Geisinger, a healthcare system known for its superior quality,” he notes. Dr. Shaheen is rated as an Experienced provider by MediFind in the treatment of Hernia. His top areas of expertise are Short Bowel Syndrome, Malnutrition, Obesity, Gastrectomy, and Gastric Bypass.

Harsh Grewal, MD, is a pediatric general surgeon. He specializes in pediatric general, thoracic and minimally invasive surgery. He also takes care of pediatric trauma patients. He has a special interest in minimally invasive surgery applications for access to the spine for children with scoliosis.|Dr. Grewal earned his medical degree from All India Institute of Medical Sciences in New Delhi. After medical school, he completed a General Surgery residency at New York Medical College, NY. He followed that with a fellowship in Pediatric Surgery at Arkansas Children’s Hospital in Little Rock, Ark. He is board certified in general surgery as well as pediatric surgery.|He serves as a journal reviewer for a number of clinical medicine publications. Dr. Grewal has also served as a medical educator, training future surgeons, and has applied for a patent for a medical device. He's had work published in numerous medical journals, books and other publications, and has presented his work at numerous conferences and symposiums around the United States and internationally.|Outside the office, Dr. Grewal enjoys traveling, trail running, hiking and trekking. Dr. Grewal is rated as an Experienced provider by MediFind in the treatment of Hernia. His top areas of expertise are Appendicitis, Hirschsprung Disease, Total Intestinal Aganglionosis, Appendectomy, and Spinal Fusion.

William Pagana is a primary care provider, practicing in Pediatrics and Internal Medicine in Middleburg, Pennsylvania. Dr. Pagana is rated as an Experienced provider by MediFind in the treatment of Hernia. His top areas of expertise are Osteoarthritis, Osteomyelitis, Osteomyelitis in Children, and High Cholesterol.