A member of our pediatrics team, Melissa Andreasen, MSN, FNP-C, is a board-certified family nurse practitioner, dedicated to providing compassionate, evidence-based care to children and adolescents. A graduate of Minot State University, Melissa earned her Bachelor of Science in Nursing in 2013 and began her nursing career as an RN with Trinity Health. She served patients in the addiction services, intensive care, and same day surgery units before shifting her focus to advanced practice nursing. While pursuing a Master of Science in Nursing from the University of Cincinnati, she worked part time as a clinical nurse instructor with Dakota College at Bottineau. She completed her Family Nurse Practitioner training 2020 and joined a private primary care practice as a family care provider, helping pediatric, adult, and geriatric patients manage the full range of acute and chronic health conditions. Melissa is board certified by the American Association of Nurse Practitioners. She loves spending time with her two children when she’s not at work.
Anal Disorders
Nancy Longfors, MD
Dr. Longfors is a board-certified general surgeon, dedicated to providing advanced, high-quality surgical care to patients of all ages. Her experience covers a broad range of minimally invasive and traditional surgical techniques, including laparoscopic procedures and Trinity Health’s da Vinci Xi robotic surgery system. Areas of specialty include surgeries of the breast, colon, gallbladder, appendix, hernia, and gastrointestinal system. Born and reared in Minnesota, Dr. Longfors graduated with high honors from Concordia College in Moorhead, MN. She earned her Doctor of Medicine from the University of North Dakota School of Medicine and Health Sciences and completed her general surgery residency at Eastern Virginia Medical School in Norfolk. She practiced general surgery at hospitals in Arizona, Minnesota, and Wisconsin. Prior to joining Trinity Health, Dr. Longfors provided general surgery services at CentraCare Health in St. Cloud, MN. In addition to being recognized for academic achievement, Dr. Longfors has been an advocate for improving patient access to surgical care, serving international medical missions in Kenya and other short-term trips in Africa. A member of the American College of Surgeons, Dr. Longfors enjoys travel, hiking, biking, and spending time with family and friends.
Joseph Stonehocker, CPNP-PC
Trinity Health is pleased to announce that Joseph Stonehocker, CPNP-PC, has joined our team of providers at Trinity Health Western Dakota in Williston. A board certified pediatric nurse practitioner, Joseph has spent the last three years serving the healthcare needs of Williston-area young people. He provides primary care to children ages 0 to 18, with an emphasis on general and acute pediatric care, annual well-child visits, and mental health support, including ADHD diagnosis and treatment. He’s also trained in various surgical procedures such as circumcision and tongue-tie correction. Originally from Canada, Joseph was reared in Edmonton, AB, and moved to the United States with his family at an early age. He graduated from Utah State University and earned both his Master of Science in Pediatric Nurse Practice and his Bachelor of Science in Nursing from UT Health San Antonio, part of the University of Texas system. A devoted husband and father, he and his wife have five children. They enjoy family time and attending youth sporting events.
William Sisa, MD
Dr. Sisa is a pediatrician, dedicated to providing holistic care that promotes the well-being of children, adolescents, and their families. He is specially trained to manage the full range of children’s physical, mental, and emotional health problems, including acute and chronic conditions, behavioral difficulties, and developmental disorders.
Dr. Sisa earned his Doctor of Medicine degree from St. George’s University School of Medicine, Grenada, and completed his pediatric residency at Lincoln Medical and Mental Health Center, a teaching hospital affiliated with Weill Cornell Medical College in New York City.
Dr. Sisa grew up in Ghana, where he won the Presidential Award for being the best student from one of the 10 regions in Ghana at the Junior High School level, after which he proceeded to Major in Science at the best high schools in Ghana. Upon completion of high school, he started a remedial school in his hometown which is currently a high school in Ghana.
He proceeded to the University of Ghana where he majored in Chemistry. Upon arrival in the USA, he worked as a quality control chemist at NicePak PDI helping to develop some of the HPLC methods used to test the Super Sani Wipe the most popular hospital disinfectant used in hospitals in the USA. Dr. Sisa was pursuing a graduate Studies in Biochemistry at The City University of NY before he decided to pursue medicine at the St. George’s University School Medicine.
During clinical years in NYC, he got interested in teaching and mentoring of high school students in the science field, and completed several hours of volunteer work teaching. During residency, he participated in various research projects and had one of his research topics presented at the Society for Academic Emergency Medicine (SAEM) 2020 Conference in Washington, DC.
He loves driving, playing volleyball, and soccer.
Robert Guttormson, MD
Robert Guttormson, MD, MHA, FACS, is a board-certified general surgeon and a Fellow of the American College of Surgeons. With a special interest in advanced laparoscopic and robotic surgery, Dr. Guttormson is dedicated to providing excellent surgical care to patients, with innovative approaches that involve less pain, less blood loss, and quicker recovery. A Minot native, he earned his Doctorate of Medicine from the University of North Dakota School of Medicine and Health Sciences and completed his general surgery residency in Saginaw, Michigan, at an affiliate campus of Michigan State University College of Human Medicine. Following residency, he practiced at Altru Health System in Grand Forks for over nine years and served as Assistant Professor of Surgery for the UND Surgical Residency. His volunteer service includes medical missions work in Niger, Africa. His wife and their four children enjoy outdoor activities and travel. He also has an interest in photography. He is looking forward to helping serve his home community as a member of Trinity’s Surgical Associates Group.
Dustin Evans, MD
A member of our General Surgery team, Dustin Evans, MD, provides safe and effective surgical care to patients, with advanced treatment options and minimally invasive techniques for a wide range of surgical procedures. He is originally from Colorado and grew up on a dairy farm in Northeast Colorado. He earned his Doctor of Medicine degree from the University of Colorado School of Medicine. He remained at UC for his general surgery internship, and completed his general surgery residency training at the University of North Dakota School of Medicine and Health Sciences. Dr. Evans’ experience is broad and includes things from working at a gold mine to volunteering as an EMT with Highland Rescue Team Ambulance Service in Golden, CO. In his spare time, he enjoys shooting sports, 4-wheeling, and spending time with his wife and four children.
Alicia Crosby, FNP-C
A member of our General Surgery team, Alicia Crosby, FNP-C, is a board-certified nurse practitioner trained to provide a wide range of services to patients undergoing surgical procedures, including patient assessment, follow-up care, and education to surgical patients. A Minot native, Alicia received her Bachelor of Science in Nursing from Minot State University and her Master of Science in Family Nurse Practitioner training from the University of North Dakota, Grand Forks. Her RN experience includes over five years of experience as a critical care nurse in Trinity Hospital’s Intensive Care Unit. She is a member of the American Association of Nurse Practitioners.
Anthony Udekwe, MD
Dr. Udekwe (Oo-dek-way) specializes in caring for children of all ages – from newborn to adolescent. He is experienced in managing a wide variety of problems ranging from infection and illness, to chronic conditions as well as developmental problems. He provides immunizations and regular checkups to help keep children healthy. A graduate of the University of Nigeria, Dr. Udekwe completed his residency in pediatrics at Children’s National Center and Howard University Hospital, both located in Washington, D.C. He is certified in Advanced Pediatric Life Support and Neonatal Resuscitation.
Diana Peterson, MD
A board certified pediatrician, originally from New Philadelphia, Ohio, Dr. Peterson earned her Doctor of Medicine degree from The Ohio State University College of Medicine and completed her internship and residency at Keesler Medical Center, Biloxi, Mississippi. She joined Minot Air Force Base’s 5th Medical Group as a staff pediatrician. She served as Chief of Pediatrics at the base hospital prior to joining Trinity Medical Group. She’s a Diplomat of the American Board of Pediatrics.
Friday Osuala, MD
Dr. Osuala is a pediatrician specially trained to manage the full range of physical, mental, and emotional health problems of children of all ages, including infections, injuries, chronic conditions, behavioral difficulties and developmental disorders. A graduate of the University of Nigeria College of Medicine, he worked as a general pediatrician at Tobago Regional Hospital in the West Indies for five years, where he provided outpatient and inpatient care for a Level 2 nursery and pediatric emergency room. He completed residency training in Pediatric Medicine at the Pediatric Department of Woodhull Medical Center, Brooklyn, NY.