Functional dyspepsia (FD), also known as indigestion, refers to organic diseases with upper abdominal pain, abdominal distension, early fullness, belching, loss of appetite, nausea, vomiting and other symptoms. Clinical syndrome. Symptoms may be persistent or recurrent, with a duration of more than a month or more than 12 months. FD is the most common clinical functional gastrointestinal disease.
