The investigators' believe that it is important to medical practice to obtain information on how expandable metal stents work in a large group of patients who have metal stents placed in the gastrointestinal system. The purpose of this research study is to collect information on the stent placement in our facility and how the patients responded to the stent placement.

Inclusion Criteria:

1. Age 18 years or older.
2. Scheduled to undergo endoscopy with placement of self-expanding stent at the University of Florida, Gainesville, FL.
3. Subject must be able to give informed consent.

Exclusion Criteria:

1. Any contraindication to performing endoscopy.
2. Participation in another research protocol that could interfere or influence the outcomes measures of the present study.
3. The subject is unable/unwilling to give informed consent.

Age 18 or older