| Clinical characteristics | CKD (N = 33) N (%) | NRF (N = 66) N (%) | Total (N = 99) N (%) | p-Value |
| Chronic epigastric pain | 32 (96.9) | 29 (43.9) | 61 (61.6) | <0.001 |
| Nausea | 13 (39.4) | 30 (45.5) | 43 (43.4) | 0.56 |
| Pyrosis | 23 (69.7) | 51 (80.3) | 74 (74.7) | 0.23 |
| Bloating | 10 (30.3) | 28 (42.4) | 38 (38.3) | 0.24 |
| Regurgitation | 5 (15.2) | 22 (33.3) | 27 (27.2) | 0.05 |
| Eructation | 20 (60.6) | 52 (78.8) | 72 (72.7) | 0.05 |
| Anorexia | 16 (48.5) | 4 (6.1) | 20 (20.2) | <0.001 |
| Asthenia | 13 (39.4) | 2 (3.0) | 15 (15.2) | <0.001 |
| Epigastric tenderness | 17 (51.5) | 30 (45.5) | 47 (47.5) | 0.67 |