Liz8200, you pm'd me quoting my answer on another post and asking if you should give the bird the metronidazole again but the other post was about a bird with diarrhea and not watery poop which is different. Just in case you are not clear on the difference, let me give you a little poopology lesson.
Birds poop consists of three different elements: urine (clear liquid which usually makes a wet stain around the poop -it's the same as human urine, basically), urates (white liquid that dries up powdery -this is what protein becomes after metabolization) and feces (the little 'wormy' looking stuff that could be dark green when they eat seeds and fresh produce or brown when they eat pellets -it can also be colored by food like when they eat pomegranate, beets, blackberries, etc).
Now, when you have diarrhea, the feces are so soft and liquidy that they end up mixing with the urine and urates and you have a large, almost uniformly colored, soft 'creamy' mass. When you have watery poop, this means that the urine output is too large so you have a much larger wet stain as well as output of urine alone (no feces and, sometimes, very little to no urates) but the feces still have 'shape'.
The urine should be clear as water, if it's colored, there is a problem. The ureates should be white or a VERY light cream color, if they are darker, there is a problem. The feces should be either green (medium dark to dark) or brown in the case of pellets but, if they are maroon or darker, there is a problem.
The first poop of the day is always bigger and softer than the following ones so one cannot say that a bird has diarrhea based on the 'morning bomb', you need to look at the other ones during the day.
When birds first eat a fresh food diet with fruit on a daily basis after been on mostly seeds or pellets, they will start off with more urine than normal but they 'adjust' it as time goes by although some species will always have more urine than others (like GCCs, for example).
Feces that look spongy (the feces look inflated and have little holes in it like a Swiss cheese) means the bird has gas so there is a problem.
Poop does not really smell bad so, if there is an unpleasant odor to them, there is a problem.
So, going by this guidelines, tell me exactly what your bird poop looks like (if you can post a picture, better still).
Unless he kept the bird in for the test for hours and hours (it requires limiting water intake and testing at precise times), your avian vet did not do an insipidus test (the regular indicator of diabetes mellitus is the glucose level in the blood but it doesn't change with insipidus -thus, the special test).





