If you can, remove any of the solid droppings with a rubber glove, and then soak him in soapy warm water for awhile to soften things. Rub off any droppings, and rinse off soap. Dry him thoroughly with a towel and use a hairdryer on low. Then examine his vent area for anything unusual, such as a prolapse of tissue, or a wound. Offer him water with a small cup. Place him in a crate or pen with his own food and water. Add some probiotics or a tsp of plain cultured yogurt to his food for a few days. Check him out with a good examine for his crop to see if it is empty, full, or puffy. Look him over for lice and mites, especially around his vent (before his bath or later, when he is dry.) Look for any other symptoms.