Double pumping cuts total time but does not speed up the rate of release of milk. Each woman is different. Breast storage capacity differs, too, and may be somewhat related to size. A small-breasted woman may need to pump more often than a woman with more glandular tissue and more storage capacity. Most women usually use only a small portion of their mammary tissue to make milk for one baby.
Breast surgery can affect milk supply.
To decrease total volume, allow more milk retention. If the baby takes all you are pumping and you need to use the stored milk, assume the baby is experiencing a growth spurt. Pump every 1 to 2 hours for a few days until supply increases. Additional fluids affect bladder function, not milk supply. A good diet and sufficient fluids will help you feel better and stay healthy.