In answer to eneamRoma (post #6)...
While enema can be a sensual experience, I don't view sensuality or sex as essential to it's enjoyment. While my pleasure experiences are usually solo and many times involve masturbation or are preparatory to anal play that's not always the case.
As a str8... I prefer to be coached in any 'performance sport' (driving, weightlifting, etc.) by a male. I have more confidence and trust in a male understanding my capabilities, what I'm feeling and in his offering real-time hints to help me deal with the situations that arise. Most women don't really know what I'm feeling inside and how I can muscularly and mentally deal with the discomfort and pleasure elements of the enema experience.
In either a medical or non-medical setting I'd far prefer to have a male administer to me. Not because I'm attracted to a male but rather, I'm more trusting that a male who has experienced a similar enema will be more understanding about what I'm feeling and how I can best exploit my inherent capabilities.
The simple statement, "... OK, I'm going to use my fingers to lube you and then guide this tube into you. You'll feel a brief tendency to erect. Just breath normally and trust that this will be brief. Ready, here we go...."
This was best illustrated during a hospital visit when I had was prepped for an air-contrast CT and MRI without benefit of the usual starvation-laxative routine. The male tech coached me through an effective cleansing series in the morning and I went through the exam in the afternoon. The gent's physical strength was an asset in getting me properly positioned and in executing pro-active massage when necessary. Had it not been for that gent's help, I would have had to wait a week to reschedule the MRI exam.