This pilot study will explore whether treatment of eosinophilic inflammation in the esophagus is associated with an improved distensibility of the esophagus. Furthermore, previous studies of the esophagus using EndoFlip only measured distensibility of the distal esophagus, specifically the distal esophagus and esophagogastric junction. Eosinophilia in EoE has been demonstrated to affect both upper, middle and lower esophagus. The aim is to measure distensibility both proximal and distal, before and after treatment.

Inclusion Criteria:

1. Presence of eosinophilia on esophageal biopsy, defined as a peak count of > 15 eosinophils per high power field (HPF) on light microscopy based on biopsies from at least 2 of the 3 biopsy segments (upper, middle and distal esophagus)

Exclusion Criteria:

1. Secondary causes of esophageal eosinophilia has been excluded, such as eosinophilic GI diseases, celiac disease, Crohn's disease, esophageal infection, hypereosinophilic syndrome, drug hypersensitivity, vasculitis, pemphigus, connective tissue diseases, graft vs. host disease
2. Age < 18 or > 65 years
3. Contraindication for biopsy, such as presence of esophageal varices, coagulopathy
4. History of esophageal surgery, gastric or esophageal malignancy, anatomical abnormality, or major primary motility disorder (such as achalasia)
5. Pregnancy
6. Prisoners

Patients presenting to the clinic and endoscopy who are undergoing endoscopy with endoflip