Barrier function and mechanisms of pathogenesis in eosinophilic esophagitis

The purpose of this research study is to learn about the structure and function of the upper GI tract epithelium (the lining of the food tube, or esophagus, stomach, and small bowel, or duodenum) in normal people and those with disease, especially those with eosinophilic esophagitis (EoE) or gastroesophageal reflux disease ("acid reflux" or GERD).