The goal of this study is to test the feasibility and the tolerability of a tethered spectrally encoded confocal microscopy (SECM) capsule and to use it to image the esophagus.

96 participants including healthy volunteers, patients with a suspicion of having Eosinophilic Esophagitis (EoE) and patients with a current or prior clinical diagnosis of EoE will be recruited and asked to swallow the SECM capsule while being awake and unsedated. The capsule is attached to a tether which allows the operator to control as well as navigate the capsule as it progresses down the esophagus using natural propulsive force called peristalsis.

As the capsule progresses, multiple 2-dimensional cross-sectional images of the esophagus are acquired. Images are analyzed at a later stage.

Inclusion Criteria:

• Participant must be a healthy volunteer
• OR participant must have a suspicion of EoE
• OR participant must have a prior clinical suspicion of EoE
• Participant must be older than 14 years of age
• Participant must be able to give informed consent

Exclusion Criteria:

• Participants with the inability to swallow pills and capsules.
• Esophageal fistula and/or esophageal strictures with a stricture diameter that is smaller than the diameter of the capsule.
• Participants with prior endoscopic ablation or resection treatment of Barrett's Esophagus (BE)