You need to follow certain prescribed dosage or schedule in a certain time and certain preparation needed as in barium enema and fleet enema. And better you can glance some enema supplies and their procedure
Is It Safe To Use 2 Fleet Enemas?
Yes!!! With both of my pregnancies I was extremely constipated and advised by my Dr. To use Fleet Enemas.. They work great and I still use them every few days so I don't get constipated.
On whom? Yourself? I wouldn't advise it. You should actually leave these up to the pros