Sexual health and fertility after treatment for colon cancer and rectal cancer

More people under 50 are being given a diagnosis of bowel cancer. Whilst sexuality is important at every stage of adult life, this trend means conversations about sex and fertility can’t be brushed aside. Surviving cancer is the priority, of course, but living well during and after treatment matters too, and sex can be an important part of that. Physical intimacy, building and sustaining relationships, and the chance to have children (if you want them) are big parts of life, and it’s only fair to acknowledge the concern that the physical side effects of  cancer treatment can often make this more difficult. This guide takes you through what to expect, why it happens, and what you can do about it.

Bowel cancer treatment can have a physical and psychological impact in men of all ages.

• Chemotherapy is designed to kill fast-growing cancer cells, but it can also affect other fast-growing cells in the body, including those involved in fertility. Chemotherapy can reduce sperm count, damage sperm quality, or cause long-term infertility. It can also affect testosterone levels, which in turn influences sexual desire and erectile function as well as body composition (fat vs muscle) and cardiovascular health.
• Radiotherapy to the pelvic area is highly effective for rectal cancer, but it does come with potential side effects. For example, it can damage blood vessels and nerves involved in erections and bladder function. It can also reduce semen volume, cause infertility, and sometimes trigger changes in testosterone production. These changes make take several years to develop.
• Surgery for colorectal cancer can be life-saving but can affect body image, confidence, and sometimes nerve function. A stoma bag, for example, can bring anxiety about attractiveness or intimacy — but many people continue full sexual lives with one once they’ve had time and support to adjust.
• When it comes to fertility preservation, sperm banking is the most common and reliable option. Samples are collected before chemotherapy or radiotherapy. These can be stored for many years and used later for IVF or ICSI (intra-cytoplasmic sperm injection). In certain cases, sperm can be collected directly from the testicles if producing a sample is difficult.
• Erectile dysfunction (which means getting an erection sufficient for penetration and orgasm) is common after pelvic radiotherapy and surgery for rectal cancer. Treatments include tablets such as PDE5 inhibitors (like Cialis/Viagra), vacuum pumps, injectable medicine, or penile implants. Don’t be embarrassed — these are standard, safe options you can ask about. Changes in libido/sex drive are also common due to fatigue, hormone changes, and the psychological impact of a cancer diagnosis. Blood tests for testosterone and other hormone levels can be worthwhile as drug treatment may help.
• Reduced semen production and even dry orgasm/ejaculation  is a common side effect of radiotherapy and whilst not harmful, it’s worth knowing about in advance so you’re not caught by surprise.

• Chemotherapy may reduce the number of eggs in the ovaries, bring on an early menopause, or temporarily disrupt the menstrual cycle. Some women recover fertility afterwards, but others may not.
• Women who undergo pelvic radiotherapy often experience new menopausal symptoms because their ovaries produce lower hormone levels, even if they have already been through the menopause. These symptoms can resolve after treatment in pre-menopausal women, but if not, hormone replacement therapy (HRT) can be a very effective, depending on your cancer type and risk profile.
• Radiotherapy can also cause thinning or scarring of vaginal tissues (causing dryness and narrowing), and this can make sex uncomfortable. Vaginal moisturizers, oestrogen creams and lubricants, and pelvic floor physiotherapy can help, as can early and consistent use of dilators. For women undergoing radiotherapy, advice and guidance from a female member of staff will be provided.
• Loss of desire or arousal is sometimes physical, sometimes psychological, and often both. Addressing dryness and pain is the first step; counselling and open conversations with your partner also matter.
• There are several options for fertility preservation. With egg freezing, eggs are collected after hormonal stimulation, frozen, and stored for future use. Embryo freezing is similar to egg freezing, but the eggs are fertilised with sperm before freezing, and tends to take longer. Ovarian suppression uses hormonal treatment (such as GnRH analogue injections) to help protect the ovaries from chemotherapy damage.

Sexual wellbeing is as much about mind as it is about body. After bowel cancer treatment, people sometimes describe feeling broken, unattractive, or anxious about rejection. A stoma bag can make people self-conscious. Fear of leakage, odour, or scars can take the edge off confidence. These strategies can really help:

• Counselling: psychosexual therapy can be transformative. It offers a safe space to explore the impact of treatment and find a path back to intimacy
• Communication: honesty with your partner is key. Many partners worry more about hurting you than about scars or stomas.

Redefining intimacy: it’s not all about penetration. Touch, closeness, and finding new ways of being together can restore confidence.

• Ask early: if fertility matters to you, raise it at your very first oncology appointment. It might feel awkward, but your team will be used to the question.
• Get referrals sorted: if you’re eligible, you should be offered referral to a fertility clinic for discussion of egg, sperm, or embryo storage. It’s important to note that many insurance companies do not fund fertility preservation even if you have a cancer diagnosis, which can mean a delay for NHS treatment, or you self-funding what’s needed.

Think contraception: even if you think treatment will make you infertile, contraception is recommended during chemotherapy and radiotherapy as treatment can harm an unborn child.

• Give yourself time: recovery is physical and emotional. Expect ups and downs.
• Get a specialist referral: don’t struggle alone. Urologists, gynaecologists, pelvic floor physios, and psychosexual therapists can all help.
• Lifestyle counts: stopping smoking, minimising alcohol, achieving a health body weight, and keeping active all support hormone levels, blood flow, and confidence.

Don’t give up on parenthood: IVF, surrogacy, and adoption remain possible paths for many. Talking through your options early gives the best chance of success.

Talking about sex as you embark on cancer treatment can feel absurd or unnecessary. Yes, some of the language is awkward, and yes, talking about dilators or erections in a hospital setting can feel surreal. But honesty and a little humour are often the best antidote to embarrassment. Some people even find it helps to share experiences in support groups or in online forums.

• Bowel cancer is affecting more younger people, making fertility and sexual health part of the conversation.
• Chemotherapy and pelvic radiotherapy can affect sperm, eggs, hormones, and sexual function — but there are many ways to reduce risks and manage side effects.
• Fertility preservation should be discussed before treatment starts if it’s important to you. During treatment, you must do everything you can to avoid pregnancy because of the risk of harm to an unborn child.
• After treatment, physical and psychological support are available — from medication to counselling.
• Intimacy may look different, but it is absolutely possible to have a fulfilling sex life after bowel cancer.
• Support is waiting, solutions exist, and with honesty and help, many people go on to live — and love — fully after bowel cancer.

Can I have sex during bowel cancer treatment?
Yes, in most cases you can still have sex during bowel cancer treatment, as long as you feel well enough. Cancer itself isn’t infectious, and you won’t harm your partner by having intercourse. What you do need to think about is contraception — chemotherapy and radiotherapy can damage an unborn child, so reliable contraception (such as using a condom) is essential even if you suspect your fertility is reduced. Some people find desire dips during treatment because of fatigue, nausea, or body changes, and that’s perfectly normal. The key is to go at your own pace, talk openly with your partner, and remember that intimacy can take many forms.

Will I ever feel like myself again in the bedroom?
There is every chance of this — though it may take time. Bodies change, and cancer treatment can affect libido, erections, lubrication, enjoyment, and confidence. It can take a while for couples to return to previous levels of sexual activity. But with the right support — whether that’s medication, physiotherapy, or psychosexual counselling — many people find a way back to a satisfying sex life. It may not be identical to before, but intimacy doesn’t disappear with cancer.

Will my partner still find me attractive?
Most partners care far more about you being alive and present than about scars, stomas, or changes in performance. Sexual desire and pleasure is as much about who you are as a person and the history you share with your partner. Worrying about rejection is normal, but honest communication usually reassures both sides. Confidence tends to grow once you’ve tested the waters together.

What if I can’t have children after treatment?
It’s a painful thought, and it’s why fertility preservation is worth discussing before treatment if you can. But even if treatment affects fertility, options like IVF, surrogacy, and adoption may still be open. What matters is knowing early what’s possible for you — and getting the right referrals.

Is sex safe after treatment?
Yes. You cannot ‘damage’ your partner or cause the cancer to spread by having sex. The only caveat is contraception: chemotherapy and radiotherapy drugs can harm a developing pregnancy, so reliable contraception is advised during and shortly after treatment.

What if I have no desire for sex at all?
Loss of interest is common — fatigue, hormones, and stress all play a part. It doesn’t mean intimacy is gone for good. Counselling, medication, and simply giving yourself permission to rediscover intimacy at your own pace can help.

Will a stoma mean the end of my sex life?
Absolutely not. Plenty of people with stomas have healthy sex lives. It can take adjustment — practical tips like using smaller bags or supportive underwear can help — but it doesn’t have to be a barrier.

What if nothing works?
Then we keep trying. There are always further steps — whether it’s different medications, devices, counselling, or simply reframing what intimacy means. ‘Nothing can be done’ is almost never true.