Table 1.
Demographic characteristics of patients in each group
| Group | A | B | C | D |
| Number | 38 | 37 | 37 | 36 |
| Age(yr; mean ± SD) | 42.2 ± 13.9 | 44.3 ± 18.0 | 44.6 ± 16.4 | 41.8 ± 17.5 |
| Female: Male (n) | 18:20 | 19:18 | 16:21 | 18:18 |
| Cause of endoscopy | ||||
| Dyspepsia | 25 | 28 | 21 | 23 |
| Reflux | 6 | 5 | 4 | 4 |
| Screening for cancer | 7 | 0 | 5 | 4 |
| Others | 0 | 4 | 7 | 5 |
No significant difference between each two groups regarding age and gender. Group A received water, group B received activated Dimethicone plus water, group C received N-acetylcysteine plus water, and group D received activated Dimethicone and N-acetylcysteine plus water.