E4 show The Sex Clinic has horrified viewers after a man admitted he hasn't cleaned his manhood properly in 24 years.

People shared their disgust on Twitter after patient Zach entered the clinic complaining of a nasty smell coming from his penis - which is known as 'Smegma'.

4 The Sec Clinic viewers were horrified to hear patient Zach hadn't washed his penis in 24 years Credit: E4

He spoke to Dr Naomi about his "penis problem" and said he'd been having issues retracting his foreskin, as well as having pain and irritation at the tip.

He even revealed the pain had been bothering him for nine months and told her he had previously "had the clap" and "caught Gonorrhea from some lass too".

As Dr Naomi got to work on his private parts, Zach squirmed and said: "Ooooh. That doesn't hurt but it's unfamiliar."

Zach admitted having caught a number of sexually transmitted diseases was "quite upsetting".

4 Dr Naomi worked on Zach's penis problem Credit: E4

Dr Naomi advised Zach to concentrate on cleaning the foreskin and give it a good scrub with a soap substitute.

But Zach, who is 24 years old, told her: "I’ve never cleaned my foreskin before."

People online were appalled by his confession, as one put it: "Where on earth do they find these people to go on this sex clinic?!

"If you can't wash your own bits then you are just looking for trouble"

Another said: "Is anyone else watching the sex clinic on E4? I am genuinely shocked at how little these people know about sexual health!"

4 Zach shocked viewers when he revealed he hasn't cleaned his penis in 24 years Credit: E4

How can you be 24 and not know how to wash your own penis properly?! I know how to do it and I don’t even have one 😂 #TheSexClinic — no❤️ (@ColleenMyQueen) February 2, 2019

Lots of talk on social media about Zach #thesexclinic It is not uncommon to see #Smegma on examination in clinic; he is NOT the only one who has experienced this problem #keeptalking #letstalkaboutsex #nojudgement #stopstigma pic.twitter.com/UYjo2SlRr4 — Naomi Sutton (@DrNaomiSutton) January 29, 2019

4 Viewers had a few words of advice for Zach after his confession Credit: E4

Another choked: "Too far! This poor lad on The Sex Clinic has just been told his willy basically needs a good wash."

The show reveals Britain’s sex secrets and wants to cut through taboos.

It follows a team of “seen-it-all” sexual health specialists offering advice on everything from fetishes to all manner of worrying lumps and bumps.

New E4 show ‘The Sex Clinic’ tackles all your Sexual Health needs

MOST READ IN TV & SHOWBIZ Exclusive up in flames Katie Price's mucky mansion set ablaze leaving firefighters to tackle inferno CAKES PANNED Bake Off judges left in hysterics by dodgy attempts to make celebs out of cake TRYLEENE From Dancing on Ice to astronomy and politics, is there nothing Myleene won't try? HURTFUL Love Island's Shaughna 'hurt' after being called a 'money grabber' full-time A Question Of Sport's Matt Dawson splits from wife of 11 years after show axe VAN-TASTIC Stacey Solomon gives £50k camper van a makeover as she sleeps on her drive FINAL FAREWELL Scottish rock star Fish reveals he's retiring from the music business 'SURPRISE' Holly Willoughby's This Morning blunder sees Lorraine catching her by surprise CHEEKY MEGS Megan Barton Hanson goes knickerless before enjoying a bath with girlfriends REAL LIFE Pregnant Kate Ferdinand reveals she 'can't stand' & is struggling with pregnancy

It comes as the latest figures reveal an STI is diagnosed every four minutes in England.

The largest proportion of people is within the 16 to 24 age bracket with dating apps like Tinder being blamed for the rise.

Got a story? email digishowbiz@the-sun.co.uk or call us direct on 02077824220.

We pay for videos too. Click here to upload yours.