This proposal is to contribute to data registry and sample bank called Pediatrics Biorepository for Gastroenterology Clinical Research. Samples collected in this study may be used for future research which plan to advance the state of science in the hopes to develop novel diagnostic approaches and identify therapeutic targets.

This is a smoking cessation study which is examining varenicline for use in reducing or quitting e-cigarettes. Half of the participants will receive a placebo pill and half will receive varenicline. All participants will be asked to complete daily, brief REDCap EMA diaries (to report e-cigarette use, other tobacco use, and record videos of medication taking) and attend research visits every 3 weeks (i.e., weeks 3, 6, 9, 12) to complete additional assessments and receive compensation for doing so.

This is a smoking cessation study which is examining varenicline for use in reducing or quitting e-cigarettes. Half of the participants will receive a placebo pill and half will receive varenicline. All participants will be asked to complete daily, brief REDCap EMA diaries (to report e-cigarette use, other tobacco use, and record videos of medication taking) and attend research visits every 3 weeks (i.e., weeks 3, 6, 9, 12) to complete additional assessments and receive compensation for doing so.

This is a smoking cessation study which is examining varenicline for use in reducing or quitting e-cigarettes. Half of the participants will receive a placebo pill and half will receive varenicline. All participants will be asked to complete daily, brief REDCap EMA diaries (to report e-cigarette use, other tobacco use, and record videos of medication taking) and attend research visits every 3 weeks (i.e., weeks 3, 6, 9, 12) to complete additional assessments and receive compensation for doing so.

This is a smoking cessation study which is examining varenicline for use in reducing or quitting e-cigarettes. Half of the participants will receive a placebo pill and half will receive varenicline. All participants will be asked to complete daily, brief REDCap EMA diaries (to report e-cigarette use, other tobacco use, and record videos of medication taking) and attend research visits every 3 weeks (i.e., weeks 3, 6, 9, 12) to complete additional assessments and receive compensation for doing so.