Media playback is unsupported on your device Media caption Health TV's Faizan Syed takes BBC News behind the scenes at Clinic Online

Sex is a taboo word in Pakistan. It is readily associated with sin, guilt and shame. But a television channel is breaking new ground by airing a weekly call-in show discussing sexual health.

In a country where fear of religious vigilantes dominates public life, it takes a lot of courage for people to open up about their sexual anxieties.

My married friends tell me that a man's sexual prowess usually goes down after the first few months of marriage. Is that true? Young male caller

And yet, it's happening on live TV.

The show 'Clinic Online' is aired on HTV (Health TV), a channel focusing on everyday lives of Pakistanis with a mix of health and lifestyle content.

And it's proving popular. Dozens of callers - men as well as women - from across Pakistan ring the show to get on air.

A wide range of issues are brought up, from sexually transmitted diseases (STDs) and infertility to questions about performance, size and satisfaction.

"He doesn't come to bed with me anymore," complains a housewife. "I have tried talking to him but he doesn't want to talk about it. What shall I do?" she asks.

Tongue-tied callers

Another caller, a young man about to get married, is worried about not being able to keep up with his partner's sex drive.

Image copyright AFP Image caption Dr Nadeem Siddiqui, the consultant who hosts the show, often has to ask several questions to get to the bottom of the caller's problem

"My married friends tell me that a man's sexual prowess usually goes down after the first few months of marriage. Is that true?" he wants to know.

Callers often sound a bit shy and hesitant. They are usually unsure of culturally acceptable sex terminology in the Urdu language. Many people struggle and use vague expressions to explain their predicament.

"I have developed that habit," says a reluctant female caller. "I think I am gaining weight because of it. How can I stop it?" she asks.

Dr Nadeem Siddiqui, the consultant who hosts the show, usually has to ask callers multiple follow-up questions to pin down the problem.

In this instance, Dr Siddiqui stares blankly at the camera for a while and then asks the caller to explain her question.

Image caption The show's popularity has taken many by surprise considering Pakistan's conservative culture

"I have developed that sex habit, you know, with a finger. I want to stop. Is there a medicine for it?" she asks in a hushed tone.

Now, most of the time Dr Siddiqui gives sensible suggestions to his callers. But every now and then, he goes off track.

After an uncomfortable pause, and a disapproving sigh, the good doctor has this advice for the female caller: "You should pray five times a day, refrain from watching inappropriate content on internet and read religious literature. You will be alright."

Questionable advice?

After the show, I asked the doctor about his controversial advice.

"I can't be seen to be doing anything against Islam, or it would cause trouble," he said.

And therein lies the problem. While the show is giving people a rare chance to speak up about their repressed health issues, the quality of advice they may be getting remains questionable.

"Most doctors in Pakistan are not competent to tackle sexual health issues," says Dr Javed Usman, a family physician at the Dr Ziauddin Medical Hospital in Karachi.

"Our medical curriculum doesn't really address the subject. So invariably, what you end up with are doctors applying value judgements based on their own cultural and religious beliefs, not medical knowledge."

To be sure, it's a tough call in a country and a society where Islam dominates virtually every aspect of public life.

Take the issue of self-gratification. Many conservative Muslims believe masturbation is forbidden in Islam, as is oral sex. But medical research shows there is nothing inherently wrong or unsafe in these practices.

Image caption Dr Usman says doctors find it difficult to separate their beliefs from medical facts when giving advice

So, when a Muslim doctor in a conservative society is asked on a live TV show about his opinion, he has two choices: he could give his medical advice and risk upsetting the intolerant religious lobby, or he can brush science aside and invoke religion.

More often than not, he chooses what's convenient, practical and in line with his own belief system.

No wonder sexual health remains a deeply misunderstood subject in this conservative society.

Myths and misconceptions prevail, even among doctors.

But some activists are trying to change that.

Empowering the people

Among them is Dr Sikander Sohani, a GP working for the health and education campaign group, Aahung. For two decades, he has worked with communities to change attitudes.

On a weekend at a school in north Karachi, he engages parents and teachers in a workshop about how to tackle some of these tricky issues.

His target audience comes from an average conservative neighbourhood. Men and women sit separately. Most women are covered in black scarves from head to toe.

Image caption Dr Sohani is trying to encourage people to take sensible decisions when it comes to their bodies

In a country where any discussion of sex is frowned upon, Dr Sohani takes a cautious, nuanced approach.

Throughout his presentation, the word 'sex' does not figure. Instead, he talks about life, body and health. When a participant mentions religion, he talks about nature.

"Sexual health is part of an overall wellbeing of an individual," he later tells me. "And what we are emphasising here is a rights-based approach to encourage safe and responsible behaviour," he says.

For him, a rights-based approach is the key to overcoming cultural and religious taboos. It is about giving individuals the skills and the knowledge to enjoy and protect their own bodies, he explains.

"Religious and cultural institutions tend to be interested in power and control over other peoples' bodies. We are trying to empower individuals to take charge and make sensible choices," he says.

As for 'Clinic Online', the chief executive of the HTV channel, Faizan Syed, says the show is going through a period of trial and error.

"Frankly, we are in an unchartered territory. Is there room for improvement? Certainly! But that doesn't take away the fact that we are providing a service that no one else has the courage or willingness to offer."