Best thing we did was to potty train!!
Every bird is different and will take potty training slightly differently. I wouldn't stress to much about your bird holding on too long and making themselves sick. I discussed this with my AV and he said most will just go...he only met one macaw that didn't and just held it until told (it was hours apparently, but he also said he had very strict handling etc)
Birds in general will make themselves go prior to flight, landing or if frightened so they can take off quicker with a predator. They usually dont go unless their is a change in activity especially in the larger parrots. So resting to active, eating to resting, waking up, being put on ground etc
My boy was trained after a week of being home at only 4 months of age. We created several places for him to go. Cage, stand, over shower, on newspaper or into a tissue. My boy was trained on praise only and not food rewards. This is just how I train all my animals. They do things because I ask not because they're driven for food. They do things because they want to make me happy. Its never a serious time for any of us. I treat them like I would a kid. Occasionally he still lets one go if stressed, scared or too much time has passed and he is uncomfortable. If we are playing together I have to remind him to go otherwise he will hold it till he cant hold any longer. He has learnt to say poopsie as hes doing one and will tug on my ear if in the car or going for walk to let me know he needs to hop off. When really desperate he tries to aim his poo of me. He did go through a stage of pooping on my husband which was on purpose. He would fly to him, poop and fly off. Lol again it was the relationship they had at time. It has improved now so hubby no longer gets pooped on. In saying that hes never pooped on the dog or in the bed. But he loves the dog and hes favorite place is my bed.
These guys are very smart. The relationship you have with them frames how the training will go, as do their personalities. My boy echo is cheeky, sometimes lazy and definitely likes to try get away with stuff if he can...but in saying that he is on his best behavior when out, away on holidays or visiting friends. If hes already gone and I ask him to go he kinda growls in displeasure at me.
To train I would suggest key word and action. Observe and time of his natural cycle. I found it was 20min during day and 40min when getting dark and then if asleep only if woken or moved. Knowing this I used it to my advantage and the times he was out at the beginning I offered a toilet break at 20min intervals. I also use the words and actions for turn around so he knows where I'd like him to aim for. This works really well out in community as we position his chair over something to poop on. We have taken training a little further now. Sometimes it's been longer that 40min and I know if I pick him up he'll go straightaway. I will tell him 'take you to toilet' so he knows to just hold a bit longer. If super desperate as soon as his rear end is over tiles he might let it go otherwise waits till on perch etc. But 'take you to toilet' also means you better be picking him up again otherwise he literally throws himself back at you lol
Another thing that I've done is if hes let one go somewhere and I'm not happy about it I say 'what's this...NO!' As I point to it looking unhappy. Sounds strict but Echo's personality is that he just runs off making fun of me repeating 'what's this' and laughing. His next poop however is were it needs to be so he gets rewarded with extra praise and kisses.
For us, having him toilet trained is the best. I just let him out and he does his thing all day long. Community access is enjoyable and i can even get him to poop on demand for the vet.
Only other important advice I'd give is work on a healthy relationship and the toilet training will be a breeze without any health impacts on the bird.
Good luck!! Please keep us posted.
