It is best not to use stimulants, but let the body work on it's own. However, eating a diet high in fiber like lettuce has a beneficial result.
If you eat 2 to five leaves of lettuce before each meal, it improves health by eliminating toxins out of the body quicker. So you can vary that and adjust for your own body, probably eating more lettuce before an evening meal will cause elimination in the morning. More than once a day is more healthy.
The idea is that we don't want toxins from eating to sit still in the body, but to move.
PS If you don't eat lettuce now, start with a small amount only.