A veiled and observant Muslim medical doctor, Ms. [Heba] Kotb is a Cairo-based sex therapist -- which makes her a pioneer in this part of the world. She combines Islam and tradition with science and modernity, encouraging her conservative and religious audience to discuss a topic largely shunned in public. Doing so, she says, will help save many a troubled marriage in the Arab world and rescue the young from inaccurate sexual information. "Sexual relations are like a gas station ... If the gas is no good, the car will break," she says. "This is what happens to marriages in...