I'm sorry that your question wasn't answered in a timely manner. We don't have many avian vets on this site. It's important to note that once a pet bird (which type do you have, please?) acts ill it's already quite ill and in need of the attention of an avian-oriented vet. This is a protective mechanism because sick birds are attacked by other birds in the wild and within their flock. Micky's symptoms of difficulty flying and diarrhea and are important symptoms but they're not pathognomonic (specifically indicative) of any one particular disorder. I suspect that his diarrhea indicates a bacterial enteritis (infection of the GI tract) and he's overall weak and so flying in that manner.
I would administer a liquid antibiotic directly into his beak and improve his diet. Let me know if you access to a liquid antibiotic - human or pet. Nutritional imbalances are a common cause of illness in our pet birds. What has Micky's diet consisted of, please? Seeds should compose less than 20% of his diet. A diet of mainly seed and nuts has excessive fat, carbohydrates, and phosphorus; marginal protein; adequate vitamin E, and are deficient in amino acids, calcium, available phosphorus, sodium, manganese, zinc, iron, vitamins A, D3 (necessary for efficient absorption of calcium), K, and B12, riboflavin, pantothenic acid, choline, and available niacin. Ideally, a balanced pelleted diet such as can be found here: www.harrisonsbirdfoods.com or here: www.lafeber.com/pet-birds should be fed as well as hard boiled egg yolk, pancakes and cornbread, the tops of fresh greens, dairy products such as yogurt and cheese, fresh fruits such as apples, pears, melon, kiwi, and berries, vegetables such as broccoli, carrots, beets, asparagus, cabbage, sweet potato, and squash, and even tiny pieces of meat.