Why would it not be appropriate to collect a urine sample directly from a Foley bag?

Why should the urine sample be labeled after it is collected instead of before it is collected?

Why should iron supplements be avoided before stool sampling?

Why is it important for a stool sample to be fresh?

Imagine you have a patient who has an order for a sputum sample; however, they have been unable to cough anything up. What strategies could you implement to encourage expectoration?