Why is my parrot regurgitating and rechewing his food lately?

by Carol Lynn
(Montreal Quebec Canada)

Recently, my Amazon 20 plus years old, appears to often bring his food back up into his beak and chew it over again. He works to get the food up by bringing on regurgitation. I wonder what might be causing this - otherwise he appears ok.

He did have a digestive disturbance recently and this appears resolved now. His weight did go down somewhat and now he is regaining. His droppings appear satisfactory.

He will be seen by an Avian Vet in a few days. In the meantime I am troubled and wonder why he is rechewing his meals, which he is taking well. He is not on a formula diet
I thank you for your response.