The Johns Division of Pediatric Gastroenterology, Hepatology and Nutrition practice at Howard County General Hospital in Columbia, Maryland is located in Suite 420 of the Medical Pavilion. Our internationally recognized expert pediatric gastroenterologists and hepatologists work together with certified nurse practitioners, nurses and dietitians to help children with a variety of gastrointestinal symptoms including chronic abdominal pain, reflux, constipation, vomiting and nausea.