Food residue in the esophagus may be caused by esophagitis, esophageal cancer and other diseases. 1. Esophagitis: this kind of disease may cause narrowing of esophagus due to infiltration of inflammation. When food enters and passes through the esophagus, a part of food may remain in the esophagus, so there may be the phenomenon of food residue, and there may be the symptoms of burning sensation of food and feeling of foreign body in the throat and so on. 2. Esophageal cancer: Usually, it will form a protruding occupying lesion in the lumen of the esophagus, which can hinder the passage of food when it enters into the lumen of the esophagus, and thus food residue can be felt. Both of the above mentioned diseases can have food residue phenomenon, which needs to be diagnosed by esophagoscopy and pathologic biopsy, and it is recommended to go to the hospital for consultation in time.