Some worms, like capillary worms and gapeworms, require worming several days in a row. I'm not saying the problem is worms, just that it could be. You might want to start weighing them, 'cause is suspect that they are probably losing weight. Can you post a picture of them and their poop?
If you can, take some fresh poop sample to a vet that is willing to do fecal floats.
X2. The green color comes from bile, if birds aren't eating extra amounts of greens, or a quick change in diet. Bile in birds is a brilliant fluorescent green. Bile is a digestive enzyme produced by the liver. After a number of metabolic processes, it passes from the liver down a duct (called the bile duct) into the bowel where it aids the digestive process. After digestion in the bowel, components of the bile are reabsorbed through the bowel wall for reuse. It the bowel is diseased, this process won't occur normally, and the result that more green bile stays in the bowel and is passed in the dropping, resulting in a green dropping. It could be that the liver is stressed and toxic from the variety of meds. Capillary worms aren't seen by the naked eye, Caecal worms are difficult to see unless the dropping is fresh and examined with bright light. Fowl cholera also affects the liver. Coccidiosis, bacterial enteritis, Histomaniasis, are a few more that cause liver damage. Choline chloride and thioctic acid in diets help detox and support liver function, so it is important to supplement water with good quality vitamins/probiotics after medicating.
