What do you do if the caregiver does not want to take care of a dirty patient?

I admire CNAs. Mom had some really good ones but then there r those who try to get away with doing nothing. Did the patient refuse to be cleaned up. Law says u can't force them. There are aides who take the no without trying to talk the patient into doing what needs to be done. I would mention it. I found that not alk aides know how to work around these situations.

You are a medical professional. You are required by law to report any sort of abuse to adult protective services.

Any caregiver would much rather share tea and cookies with their client than clean up accidents, but unpleasant tasks are part of the job description. Not reporting this to the appropriate person at the caregiving agency leaves a vulnerable person to sit in their own mess until the next person comes along, and since it is not very likely this "caregiver" is admitting to leaving the patient unattended to those in authority will never know there is a problem that needs to be corrected.

Report what you saw

I am the medical office assisting, and I saw that the other worker did not take care of him...

Find another caregiver who is a professional.

Quit. Find other work.