What to do about my sick bird...

[Eric&Rebecca]

That's a good idea. Maybe get him checked out again just to be sure. Or maybe just take some poop samples to the vet. They can test those without the bird being there. Wouldn't hurt to check

[Pajarita]

Good news! Going by your report, it seems to me that the problem was the beneficial bacteria in the intestines killed by the antibiotics AND been washed out by the diarrhea and that he is replenishing it himself but it's always recommended to give them probiotics after an antibiotic treatment (everybody should keep some in their Birdy First Aid Kit) - BTW, papaya is excellent for digestive upsets.