Loss of Appetite – Its Meaning In Gastroenterology Introduction Loss of appetite is something most individuals experience every once in a while, and is usually not a cause for concern. But if it lingers for some time, or becomes a regular event, then it signals something wrong in the body. Loss of appetite is known as ‘anorexia’ in gastroenterology, not to be confused with ‘anorexia nervosa’ which is an eating disorder concerning psychology and psychiatry.