BACKGROUND: After major abdominal surgery, patients may experience significant gastrointestinal dysfunction, including postoperative ileus. Many clinical tools are used to measure this dysfunction, but there is no patient-reported outcome measure (PROM) specific to this group. The aim of this study was to develop a new PROM for this common condition. METHODS: A four-stage approach was undertaken. Stage 1 used semi-structured interviews with 29 patients to explore experiences of gastrointestinal recovery and develop a draft questionnaire. Stage 2 solicited feedback from 18 patients and 15 clinical experts on the face validity of the proposed tool using the Questionnaire on Questionnaires (QQ-10). Stage 3 recruited 297 patients to complete the questionnaire. Principal component analysis reduced the items and identified the domain structure. Test-retest reliability and a pilot assessment of responsiveness were assessed in stage 4 in a sample of 100 patients and in a sample of 68 patients respectively. RESULTS: The interviews generated 26 subthemes across gastrointestinal recovery and general well-being. An initial questionnaire containing 44 items was developed. The QQ-10 demonstrated high value and low burden, supporting face validity. Tests to reduce the items and identify the domain structure resulted in a 15-item questionnaire across four domains (nausea, eating, well-being, and bowels). Test-retest reliability showed intraclass correlation coefficient values ≥0.7 for all domains. Pilot responsiveness was demonstrated through differences in pre- and post-surgical scores. CONCLUSION: PRO-diGI is a PROM for gastrointestinal dysfunction after major abdominal surgery that shows good psychometric properties and demonstrates face validity, reliability, and responsiveness. This now needs external validation to facilitate broader implementation.