What you're describing sounds like the natural process of aborting shoots. It shouldn't happen to all of them, but some percentage. The bamboo will start more shoots than it needs to, in case some get eaten or otherwise destroyed. But if they all survive, the bamboo will itself terminate (abort) some of its shoots. How many are growing well and how many are dying?

It's hard to say what's going on here. Bamboo like water, but don't want to be in wet soil continuously...how well does your soil drain? All that rain may have caused the fertilizer to release faster than necessary, or you may have laid it on too generously. I also suggest you try a different fertilizer in the future (or none at all). I use a slow release product with a more balanced nutrient mix (Osmocote Outdoor, 19-6-12), and I only apply it when the bamboo is getting established during the first 1-2 years. Even though bamboo is a grass, that fertilizer you used might not be ideal for growing strong bamboo.

A few of my new shoots aborted, as well - three shoots, to be exact. They were more exposed than
the others, and varied in height from two inches to fourteen inches. These shoots had also
emerged later than the others, so I figured it may have been that those culms simply missed the
critical period. When I was out in the yard yesterday, however, I noticed two new culms
shooting from the middle of the bamboo bush - with each culm about three feet long now.

Last year, the first culm that appeared (March 8th) died from two nights below freezing.
But, from the base of that culm, a new bush grew - which actually put out four smaller
shoots.

Josh