Just to add my experiences of the dreaded AG. Around 18 months we noticed we had a problem with monts, I think it started as the runs, but then the vet said one had become infected, which resulted in a GA and some antibiotics packed in to his bum.
He has to now have them emptied every 2 to 3 months, often there's only one that's full, fortunately the head vet nurse has told me she finds it quite a satisfying job to do

so i never feel bad asking, and they do it for free as we are on a plan.
We've never had any dramatic expulsions , @MF wins that prize for getting it in her hair

but we've had them on the bedspread, on my mom's trousers just before we went out for dinner, and all over my mobile phone case. Which was fortunate as if he hadn't been lying on my phone would have gone straight onto my friend's sofa.
I moan about it to the vet a bit, but 3 different vets have said that some dogs just have a lifelong issue. They hardly ever recommend removal as the complications from surgery can be horrendous, occasionally resulting in an incontinent dog.
If Monty has loose poos I can often expect leakage a day or so later, and sometimes add a few bran flakes to his food.
It started around the same time as he went on metacam, which he has daily, and i struggle to get consistently kickable poos with him whatever he eats, so this may be a minor side effect of the daily painkillers which exacerbates the anal gland issue