Diarrhea is not excessive urine in the droppings. Diarrhea is the fecal material not holding its tubular shape. Instead it is the consistency of pudding. Look for blood in the feces. If the feces is fresh and black in color and there were no blueberries in the diet then this indicates melena.
Melena is black droppings caused by bleeding high up in the digestive system.
When the blood passes through the lower digestive system, it is digested turning the red blood into a black tarry color, staining the feces black. Color which cannot be explained by the diet should be investigated by your veterinarian. Don't forget to look for real worms like tapeworms and roundworms. If you wait until the bird is weak, not eating, and fluffed up, then you have a race against the clock to save the bird's life. Watch your bird's droppings everyday and learn what they look like normally.