Answer:
If you feel that your bird's stools are of concern and you haven't changed anything in his diet, then yes, you should take him in to see your vet right away. Here is an article that discusses inspecting your bird's droppings and what is normal and abnormal.
http://www.drsfostersmith.com/pic/a...If your bird is showing any symptoms of being sick including lethargy, not eating, sitting low or huddled with or without ruffled feathers, or rattled, wheezy, or open-mouth breathing you should take him in to the vet right away. I hope that your bird is fine, but it is best to err on the side of caution, rather than wait to see if he will get worse or better.