👉 In anatomy, a hepaticoenterostomy (HEM) is an opening in the abdominal wall through which a tube or other passage connects the liver to the intestines. This procedure is used to treat gastrointestinal bleeding and surgery for certain conditions such as gallstones or diverticulitis. A HEM is also known as an ileal bypass, because it involves removing part of the intestine (ileum) from the abdomen. The ileum is the small intestine that connects the stomach to