Purpose Survivors of esophagectomy often experience delayed gastric conduit emptying, dumping, and swallowing dysfunction, which significantly impairs quality of life. Most existing studies utilize generic or cancer-specific patient-reported outcome measures (PROMs) that do not adequately capture pyloric and conduit-specific dysfunctions. Symptom assessment tools such as the Gastroparesis Cardinal Symptom Index (GCSI) have been validated in native stomachs, not in gastric conduits, and their domain structure and clinical cut points remain unevaluated in post-esophagectomy populations. As a result, reported dumping prevalence varies widely (0–78%), reflecting inconsistent definitions and the lack of standardized, conduit-specific symptom assessment. Methodology This observational study enrolls disease-free adults between 6 and 12 months following esophagectomy with gastric conduit reconstruction. Participants complete a questionnaire evaluating: (1) GCSI-derived stomach symptoms; (2) early and late dumping symptoms; (3) dysphagia, reflux, and regurgitation; and (4) functional and nutritional impact. Clinical covariates include diabetes, opioid use, and time elapsed since surgery. The primary outcome is an externally anchored composite endpoint, defined by the need for pyloric or endoscopic intervention. Results It is hypothesized that symptom clusters dominated by fullness and early satiety will more effectively identify clinically meaningful functional morbidity than nausea-predominant GCSI domains. A straightforward PROM rule that combines elevated stomach symptom scores with multiple dumping features is anticipated to identify a high-risk subgroup with increased rates of malnutrition, intervention, or significant endoscopic findings, independent of diabetes and opioid use. Conclusion This study addresses a key methodological gap in post-esophagectomy PROM research by directly evaluating whether symptom questions adapted from native stomach and oncologic tools are appropriate for gastric conduit patients.