Final answer:
The type of procedure that should be employed for suctioning a stoma is Yankauer suctioning.
Step-by-step explanation:
When it becomes necessary to suction a stoma, the type of procedure that should be employed is Option 3: Yankauer suctioning. Yankauer suctioning is a technique that uses a Yankauer suction catheter, which is a rigid, curved tube with a bulbous tip, to remove secretions from a stoma. This method is commonly used for tracheostomy suctioning and is effective in clearing the airway.