Introduction: Gastroparesis (GP) is a disorder defined by delayed gastric emptying, though diagnosing GP can be challenging for many clinicians. There is a paucity of data describing diagnostic outcomes of patients referred to a tertiary gastroenterology (GI) practice for GP. We hypothesize that the majority of patients referred for GP ultimately receive alternative diagnoses, namely functional dyspepsia (FD). Methods: A retrospective cohort population consisting of adult patients (18-90 years old) who were referred to Mayo Clinic Florida for the evaluation of GP between January 2019 and July 2021 was reviewed. Basic demographic information, medical comorbidities, medications, diagnostic tests, and labs were collected. A final diagnosis was determined by review of clinical notes and tests by experts in the field (BEL, DJC). Continuous variables were summarized with median and range, and categorical variables were summarized with frequency and percentage. Differences between misdiagnoses and correct diagnoses of GP were evaluated using the Kruskal-Wallis Rank Sum test for continuous measures and the Fisher Exact test for categorical measures. Results: 339 patients were evaluated; the mean age was 46 [range: 18-90]; 278 (82%) were female. Overall, 66 (19.5%) patients were diagnosed with GP after evaluation, whereas 273 (80.5%) patients received an alternative diagnosis (Figure); 151 (44.5%) were diagnosed with FD. Compared to GP patients, patients with alternative diagnoses were significantly younger [median age 44 vs 52, P=0.001] and had significantly lower median BMI [median 24.9 vs 28.5, P=0.017; Table]. Patients correctly diagnosed with GP were more often diabetic [40% vs 17.2%, P < 0.001), had Barrett’s esophagus [12.1% vs 4.8%, P=0.042], had undergone cholecystectomy [56.1% vs 37.7%, P=0.008], appendectomy [24.2% vs 13.6%, P=0.038] or fundoplication [13.6% vs 5.1%, P=0.025], were taking a PPI [71.2% vs 48.7%, P< 0.001], were less likely to use cannabis [9.1% vs 22.1%, P=0.034], and more often had retained food in the stomach on upper endoscopy [22.7% vs 8.8%, P=0.004]. There was no difference in GI symptoms on presentation between the patient groups. Conclusion: The vast majority of patients referred to a tertiary GI practice for evaluation of GP receive alternative diagnoses, most commonly FD. Presenting GI symptoms do not distinguish GP from alternative diagnoses, though a prior surgical history and findings of retained food on upper endoscopy may help predict a true diagnosis of GP.Figure 1.: Final Diagnoses Among Patients Referred for Evaluation of Gastroparesis Table 1. - Demographics and Relevant Historical Data of Patients Referred for Evaluation of Gastroparesis Misdiagnosis (N=273) Gastroparesis (N=66) Total (N=339) P-value Age 0.001 Median (Range) 44.00 (18-83) 52.00 (18-90) 46.00 (18-90) BMI 0.017 Median (Range) 24.89 (13.1-51.3) 28.52 (15.7-42.8) 25.34 (13.1-51.3) Sex 1.000 Female 224 (82.1%) 54 (81.8%) 278 (82.0%) Male 49 (17.9%) 12 (18.2%) 61 (18.0%) Race 0.842 White 231 (85.6%) 57 (87.7%) 288 (86.0%) Non-White 39 (14.4%) 8 (12.3%) 47 (14.0%) Diabetes < 0.001 Type I 18 (6.7%) 11 (16.9%) 29 (8.7%) Type II 28 (10.5%) 15 (23.1%) 43 (13.0%) GERD 195 (71.4%) 48 (72.7%) 243 (71.7%) 0.880 Barret's Esophagus 13 (4.8%) 8 (12.1%) 21 (6.2%) 0.042 H.pylori 17 (6.2%) 2 (3.0%) 19 (5.6%) 0.549 Depression 110 (40.4%) 21 (31.8%) 131 (38.8%) 0.208 Anxiety 157 (57.5%) 36 (54.5%) 193 (56.9%) 0.680 Cholecystectomy 103 (37.7%) 37 (56.1%) 140 (41.3%) 0.008 Fundoplication 14 (5.1%) 9 (13.6%) 23 (6.8%) 0.025 Appendectomy 37 (13.6%) 16 (24.2%) 53 (15.6%) 0.038 PPI 133 (48.7%) 47 (71.2%) 180 (53.1%) < 0.001 NSAIDs 50 (18.4%) 11 (16.7%) 61 (18.0%) 0.859 Opioids 41 (15.0%) 8 (12.1%) 49 (14.5%) 0.697 Cannabis use (current) 59 (21.7%) 6 (9.1%) 65 (19.2%) 0.034 Alcohol use (current) 103 (37.7%) 19 (28.8%) 122 (36.0%) 0.256 Tobacco use (current) 37 (13.6%) 4 (6.1%) 41 (12.1%) 0.241 Nausea 241 (88.3%) 61 (92.4%) 302 (89.1%) 0.388 Vomiting 174 (63.7%) 49 (74.2%) 223 (65.8%) 0.114 Satiety 98 (35.9%) 19 (28.8%) 117 (34.5%) 0.314 Abdominal pain 209 (76.6%) 50 (75.8%) 259 (76.4%) 0.873 Bloating 104 (38.1%) 23 (34.8%) 127 (37.5%) 0.672 Prior EGD Normal 107 (39.2%) 21 (31.8%) 128 (37.8%) 0.322 Retained Food on Prior EGD 24 (8.8%) 15 (22.7%) 39 (11.5%) 0.004