large crop

[chicken]

I have a yellow crested Amazon. He is about 10 years old. He started regurgitating several times a day about a year and half ago. We took him to the vet. They kept him for 3 days, did all kinds of tests but found nothing wrong with him. They said he is probably in love with someone or something in the house. Since then he has developed a very large crop and regurgitates many times a day. The only time we think he doesn't regurgitate is when he is in his outside cage.

My question is: How do we stop this, if it's even possible?

It is really gross and is driving me crazy! I attempted to put a "crop bra" on him today, but of course, he wasn't going to let that happen.

Nancy