What is his mental state? I mean, besides his issue with perceiving half of his body only, how does he function otherwise. Maybe, others with this same issue will respond, but, I think that I might insist that he be accompanied to the bathroom each time, so you can assist him in cleaning him up properly. I don't know of any way that you will teach him how to do it better. You may need to lock the bathroom door, so he must get you to get inside. Accepting help will be something he must adjust to.
I see that he has Lewy Body Dementia, but, my question about his mental state was regarding how well he was functioning. Such as does he have delusions that would prevent him from properly using the toilet or does he have hallucinations that prevent him from understanding that he needs to be accompanied to the bathroom. Apparently, there is some kind of distortion that prevents him from proper use of the toilet. Maybe, I should have asked what stage, though, that is sometimes a difficult question to answer.
I think id9also want to know if he's had a stroke that has resulted in him not "perceiving" one side of his body, and what can be done therapeutically to ameliorate that condition.
Lewy Body Dementia often involves depth perception issues. (Which, oddly enough, can fluctuate from day to day.) It may be that LBD alone accounts for your husband's problems positioning himself regarding the toilet. But just to be safe, I'd discuss it with his doctor to see if he should be tested for other causes.
My husband (LBD) could not perceive how to position himself to get into bed so that he fit between the headboard and foot board. I had to place my hand on the mattress and say "sit here, dear" and then help him get into bed from there.
It may be that the only practical solution is for you to supervise your husband's visits to the bathroom.
He was diagnosed with LBD 3 yrs ago. At that time they also found that he had a silent stroke that is affecting the right side of his body. They were not able to tell how long ago that was but in retrospect it probably was about 5 years ago. He has halicinstions which were very bad when he was first diagnosed but medication has helped. Hope this answers all of your questions.
Is there some reason that you are hesitant to insist on supervising his bathroom visits? It sounds like he has a lot of challenges that really are not going to allow him to handle this alone.
He will reach the point where he needs skilled nursing care. Much of that decision is up to you. Your own health should not be jeopardized. So talk to the MD about aides to do some of the care for him. Call your county office of the aging and ask about services in the home.
My husband (LBD) could not perceive how to position himself to get into bed so that he fit between the headboard and foot board. I had to place my hand on the mattress and say "sit here, dear" and then help him get into bed from there.
It may be that the only practical solution is for you to supervise your husband's visits to the bathroom.
Hope this answers all of your questions.