Dr. Still is a board-certified and fellowship-trained specialist in nutrition and weight management. His clinical and research interests include malnutrition and comprehensive weight management. Dr. Still obtained his medical degree from the Philadelphia College of Osteopathic Medicine. He completed his residency and a fellowship in clinical nutrition at Geisinger Medical Center. Dr. Still is certified by the American Board of Internal Medicine.|Are weight loss medications right for you? Learn more from Dr. Still. Dr. Still is rated as an Elite provider by MediFind in the treatment of Obesity. His top areas of expertise are Obesity, Malnutrition, Small Bowel Bacterial Overgrowth, Gastric Bypass, and Vagotomy.

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 an Elite provider by MediFind in the treatment of Obesity. His top areas of expertise are Obesity, Hiatal Hernia, Hernia, Gastric Bypass, and Endoscopy.

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 a Distinguished provider by MediFind in the treatment of Obesity. His top areas of expertise are Hiatal Hernia, Hernia, Obesity, Gastric Bypass, and Endoscopy.

Peter Benotti is a General Surgeon in Danville, Pennsylvania. Dr. Benotti is rated as a Distinguished provider by MediFind in the treatment of Obesity. His top areas of expertise are Obesity, Urachal Cyst, Gastric Bypass, and Knee Replacement.

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 Obesity. His top areas of expertise are Hiatal Hernia, Obesity, Hernia, Gastric Bypass, and Endoscopy.

Conor Mulcahy, DO, is an internal medicine physician. He cares for adults with a range of chronic and acute conditions. “I enjoy being a ‘Jack of all trades’ but have a particular interest in optimizing lifestyle to help patients live healthier lives,” he says.|Dr. Mulcahy earned his medical degree from Lake Erie College of Osteopathic Medicine in Erie. After medical school, he completed a residency at Geisinger Medical Center, where he was resident of the year.|“I love the longitudinal relationships I get to have with patients,” he notes. “I also have a passion for teaching.”|In his spare time, Dr. Mulcahy enjoys ultimate Frisbee and hiking. Dr. Mulcahy is rated as an Advanced provider by MediFind in the treatment of Obesity. His top areas of expertise are Obesity, High Cholesterol, Glucocorticoid-Remediable Aldosteronism, and Familial Hypertension.

Daniela Hangan is a primary care provider, practicing in Family Medicine in Danville, Pennsylvania. Dr. Hangan is rated as an Advanced provider by MediFind in the treatment of Obesity. Her top areas of expertise are Malnutrition, Small Bowel Bacterial Overgrowth, Short Bowel Syndrome, and Obesity.

William Cochran is a Pediatric Gastroenterologist in Danville, Pennsylvania. Dr. Cochran is rated as an Advanced provider by MediFind in the treatment of Obesity. His top areas of expertise are Obesity, Meckel's Diverticulum, Atresia of Small Intestine, and Childhood Volvulus.

Christine Hanna is a primary care provider, practicing in Gastroenterologist in Danville, Pennsylvania. Dr. Hanna has been practicing medicine for over 10 years and is rated as an Experienced provider by MediFind in the treatment of Obesity. Her top areas of expertise are Malnutrition, Obesity, Short Bowel Syndrome, and Small Bowel Bacterial Overgrowth.

Dr. Hosterman is a board-certified and fellowship-trained specialist in nutrition and weight management. Her clinical interests include adult and pediatric malnutrition and comprehensive weight management. Dr. Hosterman attended the Philadelphia College of Osteopathic Medicine, where she received her medical degree. She completed her internal medicine – pediatric residency and then her weight management and nutrition fellowship at Geisinger Medical Center. Dr. Hosterman is certified by the American Board of Internal Medicine, the American Board of Pediatrics, the American Board of Obesity Medicine and the American Board of Physician Nutrition Specialists. Dr. Hosterman is rated as an Experienced provider by MediFind in the treatment of Obesity. Her top areas of expertise are Malnutrition, Short Bowel Syndrome, Small Bowel Bacterial Overgrowth, and Protein Deficiency.

Amitpal Singh Johal, MD, is a board-certified and fellowship-trained gastroenterologist, also known as a GI doctor. He has a special interest in endoscopic ultrasound, a minimally invasive procedure used to evaluate and diagnose digestive diseases.|Dr. Johal earned his medical degree from the Medical College of Wisconsin. He completed his residency in internal medicine at University Hospitals Case Medical Center in Cleveland and his fellowship in gastroenterology at Geisinger Medical Center.|Dr. Johal is certified by the American Board of Internal Medicine in gastroenterology. Dr. Johal is rated as an Experienced provider by MediFind in the treatment of Obesity. His top areas of expertise are Nonalcoholic Steatohepatitis (NASH), Benign Esophageal Stricture, Lower Esophageal Ring, Endoscopy, and Colonoscopy.

Harshit S. Khara, MD, is an Interventional Gastroenterologist based at Geisinger Medical Center in Danville, PA.|Dr. Khara is an Associate Professor of Medicine at the Geisinger Commonwealth School of Medicine. He serves as the Director of Endoscopy; System Director of Interventional Endoscopy, Director of Endoscopic and Translational Research; Director of the Clinical Use Evaluation Committee; and System Director of Quality & Innovation. He is also the Research Director and Core faculty for the Gastroenterology Fellowship Program, as well as the Program Director for the Advanced Therapeutic Endoscopy Fellowship Program at the Center for Advanced Therapeutic Endoscopy at Geisinger, participating in the training and mentoring of advanced endoscopy and general gastroenterology fellows. Dr. Khara is also the Director of the National Pancreas Foundation Center at Geisinger.|He is involved in multi-center clinical research and quality improvement projects. Dr. Khara's clinical and research interests are in the field of interventional endoscopic ultrasound, ERCP, Barrett’s esophagus, third space endoscopy, endoscopic treatments for GERD, interventional EndoHepatology, and bariatric interventional endoscopy.|Dr. Khara earned his medical degree from Seth G.S. Medical College & K.E.M. Hospital in India then completed his Internal Medicine Residency at Drexel University College of Medicine-Saint Peter's University Hospital. He completed a Fellowship in Transplant Hepatology at the University of Nebraska Medical Center, a Fellowship in Gastroenterology at Yale University School of Medicine-Norwalk Hospital and a Fellowship in Advanced Therapeutic Endoscopy at Geisinger Medical Center.|Dr. Khara is certified in Gastroenterology by the American Board of Internal Medicine. Dr. Khara is rated as an Experienced provider by MediFind in the treatment of Obesity. His top areas of expertise are Pancreatic Pseudocyst, Gastroesophageal Reflux Disease (GERD), Barrett Esophagus, Endoscopy, and Gastric Bypass.

Dr. Confer is a board-certified and fellowship-trained gastroenterologist. His clinical interests include endoscopic ultrasound and endoscopic retrograde cholangiopancreatography (ERCP). Dr. Confer attended the Lake Erie College of Osteopathic Medicine, where he received his medical degree. He completed his residency, a fellowship in gastroenterology and hepatology, and a fellowship in advanced therapeutic endoscopy at the Cleveland Clinic Foundation. Dr. Confer is certified by the American Board of Internal Medicine in gastroenterology. Dr. Confer is rated as an Experienced provider by MediFind in the treatment of Obesity. His top areas of expertise are Gallbladder Disease, Benign Esophageal Stricture, Cholecystitis, Endoscopy, and Gallbladder Removal.

Dr. English is a board-eligible physician specializing in family medicine. Her clinical interests include preventive medicine. Dr. English attended the Lake Erie College of Osteopathic Medicine, where she received her medical degree, and completed her residency at Geisinger Wyoming Valley Medical Center. Dr. English is rated as an Experienced provider by MediFind in the treatment of Obesity. Her top areas of expertise are Boils, Folliculitis, Carbuncle, Kidney Stones, and Thyroidectomy.

Ulonna Ahipue, MD, is an internal medicine physician who provides comprehensive care for adults. She treats a wide range of health concerns — from chronic conditions to new medical issues.|Dr. Ahipue has a special interest in women’s health and preventive medicine, aiming to help her patients live healthier lives through proactive care and education. She earned her medical degree from St. George's University and completed her residency at Danbury Hospital in Connecticut.|In her free time, Dr. Ahipue enjoys traveling and the culinary arts. Dr. Ahipue is rated as an Experienced provider by MediFind in the treatment of Obesity. Her top areas of expertise are Maturity Onset Diabetes of the Young, Type 2 Diabetes (T2D), Postmenopausal Osteoporosis, and Osteoporosis.

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 Obesity. His top areas of expertise are Short Bowel Syndrome, Malnutrition, Obesity, Gastrectomy, and Gastric Bypass.

Susan Rasul is a primary care provider, practicing in Gastroenterologist in Danville, Pennsylvania. Dr. Rasul is rated as an Experienced provider by MediFind in the treatment of Obesity. Her top areas of expertise are Malnutrition, Small Bowel Bacterial Overgrowth, Short Bowel Syndrome, and Obesity.

Lovepreet Singh is a Gastroenterologist in Danville, Pennsylvania. Dr. Singh is rated as an Experienced provider by MediFind in the treatment of Obesity. His top areas of expertise are Acute Pancreatitis, Childhood Pancreatitis, Heart Failure with Preserved Ejection Fraction (HFpEF), Endoscopy, and Liver Transplant.

Harini Rathinamanickam is a Transplant Surgeon and a Gastroenterologist in Danville, Pennsylvania. Dr. Rathinamanickam is rated as an Experienced provider by MediFind in the treatment of Obesity. Her top areas of expertise are Visceromegaly, Non-Alcoholic Fatty Liver Disease, Gardner Syndrome, Endoscopy, and Colonoscopy. Dr. Rathinamanickam is currently accepting new patients.

Voranaddha Vacharathit is a General Surgeon in Danville, Pennsylvania. Dr. Vacharathit is rated as an Experienced provider by MediFind in the treatment of Obesity. Her top areas of expertise are Hernia, Gastroesophageal Reflux Disease (GERD), Congenital Diaphragmatic Hernia, Gallbladder Removal, and Gastric Bypass.