This is why patients must be kept informed about any new information about their states of health and the treatments they are receiving.
Why then does the AMA absolutely prohibit sexual relationships with consenting adult patients?
Perhaps it would be too expensive or time-consuming to scrutinize the propriety of these relationships and the effectiveness of consent on a case-by-case basis.
For example, the Supreme Court of the United States has upheld maximum age limits for police officers against the challenge that they violate the Constitution by depriving the officers of the ability to show that they in fact are physically capable of doing the job past the age cut-off.
Or perhaps the AMA feels that there simply are no circumstances in which a patient could give valid consent.
Depending on the reason for the patient's visit, doctors give diagnoses, order treatments and check on the progress of patients.