It's pretty standard behavior for growth like this in a newly transplanted bamboo. (And, by the way, it's "culm," not "clum"). If you cover the part of the new culm that's parallel to the ground with dirt, it may put down some roots from the nodes; if so, and once the roots are well established, you could sever the connection between the main plant and the new roots, and either pot up the division, or replant it elsewhere. As the main plant matures, you will likely have new shoots come up much straighter. If you have a dying culm, I'd leave it for a while; it won't hurt and it may re-leaf. If it doesn't and the culm turns tan, you can cut it down.