It sounds like not enough water coupled with a new (possibly transplant-shocked) plant and high temperatures.
Did the plant you bought have a decent size rootball and was it moist when it arrived? If you get more bamboo, we can probably suggest better places to buy than off eBay.

One more thought. You can get a moisture meter at your local nursery or Home Depot for $3-$7, which should help you monitor things better. I've given up on the finger-in-the-soil approach because it's too variable and subjective.

Although you can usually tell if a bamboo needs water because its leaves will curl up longitudinally, you might not get this warning with a young plant that's not well-established before damage occurs.

If what you got is just a rhizome, what I think is happening is that there is simply not enough root mass to support any new shoots. I've tried planting rhizomes in containers this spring and a few have sent up small grassy shoots as you described, and then simply just died.

I bought what was called a 5 gallon plant, so I am not sure if it is a rhizome or not. The one little shoot has now turned totally brown and vanished. It was moist when it arrived and upon planting. It seemed to be doing well for about 3 weeks with new sprouts coming out, but none really took off like I expeected. I am going to try to revive this one, but would love to buy another if anyone can make a suggestion of where to buy. Thanks, Sheila

Shiela-
The questions about rhizomes were only to ask if you got simply a piece of root, or actually a whole plant, i.e., a root ball (which contains the rhizomes), plus one or more culms (the aboveground growth). If you were buying from a reputable nursery, you would have gotten a whole plant (although the culm(s) might have been shortened for shipping). There are plenty of places to get black bamboo, and if you say what town you're in, we could possibly recommend somewhere close by to drive to, or a reliable mail order bamboo nursery.

I guess what I got was a root ball ( I am not familiar with the terminology - I guess a rhizome is a piece of root that has not developed shoots?) with a 4 foot culm. I live in Waco, Texas and have looked all around here with no success. I would be grateful to hear of a place to get a plant from someone reputable. Thanks in advance! Sheila

Look at the ABS site below and scroll down to search by State.

ABS Bamboo Nurseries

Kt

Could your bamboo have gotten too much nitrogen from the pheasant manure? Maybe the combination of plant food and guana got the best of it.

if the leaves on the culm are still alive you may get more new shoots next spring from this plant . many posts in this forum will tell you not to give up on bamboo even if it looks dead, for at least a year.