Achalasia: A rare motor disorder of the esophagus characterized by inability of the lower esophageal sphincter and esophageal muscle to relax as well as dilation of the esophagus.
Chagas disease: A parasitic infection caused by the protozoa Trypanosoma cruzi and transmitted by insect bites or blood transfusions. The disease primarily involves the heart and gastrointestinal system.
Scleroderma: A rare, progressive connective tissue disorder involving thickening and hardening of the skin and connective tissue. There are a number of forms of scleroderma with some forms being systemic (involving internal organs).