I don't think it's anything serious; a few of mine do that. Sometimes brown tips are indicative of too much watering. At this time of year, there may also be some leaf change-out happening. Do you fertilize your bamboo?

I hardly ever fertilize, maybe 15-15-15 once a year. You may be on to something about the overwatering, I need to cut back on that. Thanks,

I think you are about right on the fertilizer, so cut back some on watering. You will know if you are giving the bamboo too little water if the leaves start curling inward on themselves along their length and look like little tubes starting to form. This is their way to conserve water when they are getting dry.

In any case, your bamboo does not have a disease nor is it in any danger of croaking!