Final answer:
To ensure the effectiveness of a rectal suppository, it should be pushed deep into the rectum and the patient should lie on their left side after insertion.
Step-by-step explanation:
The best way to ensure the effectiveness of a rectal suppository is to push it deep into the rectum. By inserting the suppository deep into the rectum, it ensures that the medication is delivered to the intended site of action. Lying on the left side after insertion is also recommended as it allows gravity to assist in the absorption of the medication.
Keeping the patient standing or holding the suppository in the hand for a few minutes before insertion does not have a direct impact on the effectiveness of the suppository.