How can I ensure that laser hair removal will be safe and effective in an area where skin pigmentation varies widely?

I have always had troubles with the skin in my groin and inner thighs that make the whole area look and feel unpleasant. I have been considering laser hair removal but I have an olive skin tone that varies. In particular, I have extensive patches of dark pigmentation from chafing. My genitalia is also darker. How would a doctor or nurse make adjustments for that variation? What questions should I ask to be sure that I will be treated safely? How might the laser affect the pigmentation?