Every part of the digestive system has a job to do, and damage to any one of the parts interferes to some degree with effective digestion. Dental problems can interfere with chewing, for example. The salivary glands can become infected, most often by the mumps virus, but sometimes by bacteria. The salivary glands rarely may develop small stones or a benign tumor. Stones or tumors can be removed easily by a physician.
Benign tumors can also affect the tongue.
The tongue and esophagus are also subject to cancerous tumors, which can spread rapidly if not removed or treated early. Such tumors, benign or malignant, are rare. But other parts of the digestive tract are more likely to develop cancer. One possible cause for cancers of the digestive tract is exposure to many different chemicals in food. In addition, inheriting certain genes is known to make specific kinds of digestive system cancer more likely.