Has anyone who has experience toilet training had personality changes as a result?

No. No changes at all.

Some months ago i had my 1st confrontation with browns. During an interrogational kind of whipping, my mistress forced me to confess some of my darkest desires. It went on and on, i was drifting away in talking rubbish, but she kept on pushing. She wanted to know if i would dream about having sex with her or other unappropriate thoughts... and there, i told her about my darkest dream to endure the ultimate form of humilation one day...

i've allready consumed her golden, but brown is on of her list of taboos. So i felt save mentioning this to her. She left the room for some time, then she released me from the whipping bench an i knelt in front of her, massaging her feets. She looked deep in my eyes and told me: 'I am more cruel, whicked and sadistic as you ever imagined... go to the bathroom, I have left something for you in the toilet bowl. Kneel before the toilet and have a close look at my devine poop' And there i was, kneeling in front of a toilet, my nose about 1-2 inches away from her stool.... That was utterly humilating and she enjoyed watching me in such a hilarious pose, before she flushed it down.

Some weeks later, quite at the start of the session, i was ordered instantly into the shower, where she squatted above my head and dumped a little log directly into my mouth. This took my by surprise, didn't expect this at all! i, surprisingly, managed not to puke... she turned around and added some golden to the experience of awful taste. She made a lot of fun about me, humilated me deeply, kicked my dick/balls with her boots or spat an me, before she 'allowed' me to swallow. Which i did. utterly humilated.

For me / us:
No problems at all. No health or mental issues. Our 'relationship' didn't change either. We had a nice talk / chit chat after the session, finishing up a bottle of champagne.
And my devotion to her went even stronger.