You don't need to cut them back. You can just repot them in larger pots occasionally as they get larger. As a general rule when a plant is more than 3 times the width of the pot it can be repotted in a larger size pot. With tall narrow plants this doesn't work as well as a rule of thumb. If you feel a plant is getting too large for the pot slide it out of the pot a little and look at the exterior of the root ball. If the roots are filling the outside of the root ball the plant is starting to get pot bound and can be moved to a larger size pot.
If any of the leaves start looking bad you can cut them back to where they attach to the trunk. If these plants are not true bamboo but rather are a type of Dracaena, also sometimes called "bamboo" then you can trim entire stalks back as far as you like if they get too long and lanky. They will resprout below the cut spot.
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