Sexual Problems After Rectal Cancer Treatment: Why Women Are Still Missing From the Research

Table of Contents

• Key Points
• Background: Why This Research Matters
• How the Researchers Did This Study
• Key Findings: What the Review Covered
• Which Questionnaires Were Used
• Who Took Part: Men Outnumbered Women
• Reporting Gaps: Where the Data Fell Short
• Quality of the Evidence
• Clinical Implications: What This Means for Patients
• Limitations: What the Study Could Not Prove
• Recommendations
• Frequently Asked Questions
• Source Information

Key Points

• A review of 25 studies covering 4,071 patients found sexual problems after rectal cancer treatment are measured inconsistently, and women are badly under-represented in the research.
• About two-thirds of participants (65.8%) were men; in five studies, women were excluded from sexual outcome analyses or statistical models without any stated reason.
• Research has focused mainly on men, particularly erectile and ejaculatory dysfunction, while female problems such as pain during sex, vaginal dryness and reduced desire are studied far less often.
• Routine follow-up often skips sexual health, and a Macmillan report found these problems are often forgotten or not discussed, despite their impact on daily life.
• The authors call for standardised, sex-specific reporting, a core outcome set, proper inclusion of women, and recording of contextual factors such as sexual activity and menopausal status.

Background: Why This Research Matters

Colorectal cancer is the fourth most common cancer in the United Kingdom, accounting for around 11% of all cancer diagnoses. Rectal cancer makes up roughly one-quarter of those cases. Better surgery, radiotherapy (radiation treatment) and chemotherapy (drug treatment) have improved survival, so more patients now live for years after treatment.

That success has shifted attention to long-term quality of life. Sexual dysfunction (problems with sexual desire, arousal, comfort or function) is a well-recognised side effect of rectal cancer treatment. It can substantially affect quality of life and emotional wellbeing. Yet routine follow-up often skips the topic entirely.

The existing research has a clear bias. Most studies focus on men, particularly erectile dysfunction (difficulty getting or keeping an erection) and ejaculatory dysfunction (problems with ejaculation). Female sexual problems are studied far less often. These include dyspareunia (pain during sex), vaginal dryness and reduced desire. An earlier review by Lee and colleagues also highlighted sex-based disparities in rectal cancer surgery and noted that much of the sexual dysfunction literature remains male-centred.

Several factors may explain the gap. Some studies suggest women are more reluctant than men to discuss sexual issues with their clinical team. A report from the cancer charity Macmillan found that sexual function problems are often forgotten or simply not discussed, despite their impact on daily life. International survivorship guidance from the National Comprehensive Cancer Network (NCCN) and the American Society of Clinical Oncology (ASCO) recommends routine, multidomain assessment of sexual health, including emotional and social context.

Cancer services also rarely collect the information that would make sexual health research more inclusive. Sexual orientation, sexual practices, preferences and menopausal status are seldom recorded. This review set out to answer two questions. First, how do the reporting and assessment of sexual dysfunction differ between men and women after rectal cancer treatment? Second, which specific domains of sexual dysfunction do the questionnaires in these studies actually measure?

How the Researchers Did This Study

This was a systematic review with a narrative synthesis. A systematic review gathers all studies on a question using a preset, reproducible method. A narrative synthesis summarises the findings in words rather than pooling the numbers, which is used when studies differ too much to combine. The work followed PRISMA reporting guidelines and was registered in advance with PROSPERO (an international register of systematic reviews) under the number CRD420251178502.

The team searched six databases: PubMed/MEDLINE, EMBASE, Scopus, CINAHL Plus, PsycINFO and the Cochrane Library. The initial search covered March 1995 to March 2025. An updated search ran to 25 March 2026.

Studies were eligible if they included adults aged 18 or older who had been treated for rectal cancer and whose sexual function was measured with the International Index of Erectile Function (IIEF) or the Female Sexual Function Index (FSFI). Those two questionnaires were chosen because they are the most commonly used sexual function tools in this field. Other patient-reported outcome measures (PROMs — questionnaires that patients complete themselves) were accepted where sexual function items could be extracted.

The researchers excluded studies of patients under 18, studies of colon or anal cancer without a clear separation of rectal cancer patients, palliative or non-curative treatment settings, non-English publications, case reports, case series, letters, editorials, conference abstracts, commentaries and reviews. Where study populations overlapped, the study with the largest sample and longest follow-up was kept.

Two reviewers extracted data independently using a standardised form piloted on a subset of studies, and a third reviewer resolved disagreements. Methodological quality was assessed with the RoB 2 tool for randomised controlled trials and the MINORS tool for observational studies. Under MINORS, scores were graded high (at least 13 of 16, or at least 19 of 24), moderate (9–12 of 16, or 13–18 of 24) or low (8 or less of 16, or 12 or less of 24). The researchers predefined 12 months after surgery as adequate follow-up. Certainty of the evidence was judged narratively across risk of bias, consistency, directness, precision and completeness of reporting.

Key Findings: What the Review Covered

The search identified 2,467 records. After removing 918 duplicates, the team screened 1,549 titles and abstracts and excluded 1,358 of them. Ninety-four full-text articles were assessed for eligibility, and 21 studies met the inclusion criteria. The updated search produced 31 more records, of which 4 were eligible. The final total was 25 studies.

Together those 25 studies included 4,071 patients. Sample sizes ranged from 40 to 948 participants, and mean ages ranged from 53 to 66 years. Twelve studies were prospective (patients followed forward in time), 11 were retrospective (looking back at existing records) and 2 were randomised controlled trials. Six were multicentre studies. Follow-up ranged from a few weeks to 4 years. Included studies came from a wide range of countries, including the UK, USA, China, Japan, Korea, the Netherlands, Australia, Canada, Spain, Italy, Germany, Taiwan, Thailand, France, the Czech Republic and Austria.

Because the studies were so different from one another — a problem known as heterogeneity — the team could not perform a meta-analysis (a statistical method that pools results into a single combined estimate). They used a narrative synthesis instead.

Which Questionnaires Were Used

Most studies used validated questionnaires, but the choice of instrument varied widely, and results were often reported selectively or without detail. Here is the breakdown:

• 13 studies used the short IIEF-5, a five-item questionnaire. It mainly assesses erectile function, with one item on intercourse satisfaction.
• The longer IIEF-15 measures multiple domains, including orgasmic function, sexual desire and overall satisfaction.
• For women, 6 studies used the FSFI-6, one used the FSFI-9, one used the IFSF and one used the IFSI. The remaining studies used the full FSFI-19.

Several studies also used questionnaires that measure urinary or bowel function. These included the International Prostate Symptom Score (IPSS), the Bristol Female Lower Urinary Tract Symptoms questionnaire (BFLUTS), the Low Anterior Resection Syndrome (LARS) score, the International Consultation on Incontinence Questionnaire for Male Lower Urinary Tract Symptoms (ICIQ-MLUTS) and the equivalent female version (ICIQ-FLUTS).

Other studies used broad quality-of-life tools such as the EORTC QLQ-C30, EORTC QLQ-CR29, EORTC QLQ-CR38 or SF-36. These contain only a limited number of sexual health items, which restricts how much detail they can provide.

Who Took Part: Men Outnumbered Women

The imbalance was clear across almost every study. Of the 4,071 participants, 2,679 were male (65.8%) and 1,392 were female (34.2%).

At the level of individual studies, female representation ranged from 22% to 50%, with a median of 35%. The one study that reached 50% enrolled participants as heterosexual couples, which balanced the sexes by design. In all other studies, women made up roughly one-quarter to one-third of participants. Male representation ranged from 50% to 78%, and six studies reported a population that was more than 70% male.

Assessment timing also varied. Most studies took a baseline measurement and then followed up around the first year after surgery, commonly at 3 months and 12 months. Two studies assessed patients earlier, after radiotherapy and after chemotherapy. One study used different follow-up schedules depending on which operation the patient had. Six studies used a single one-off survey with no repeat measurements.

Only four studies reported subgroup analyses based on the type of surgery, and just one reported subgroup analysis based on whether the patient had a stoma (an opening on the abdomen for waste). Sexual activity status, sexual preference and menopausal status were rarely recorded at all.

Reporting Gaps: Where the Data Fell Short

Reporting was inconsistent, and detailed results were uncommon. Of the 25 studies:

• 14 studies reported total scores only, with no breakdown by domain.
• 8 studies reported both total and domain-level results.
• 3 studies provided domain-level results only.

In terms of who was studied, all but three studies reported male and female sexual function separately. Those three restricted sexual function assessment and analysis to male patients only. In total, the review found that five studies excluded the female cohort from sexual outcome analyses or from statistical models, and no clear justification was given.

Thirteen studies reported adjusted analyses that accounted for other influencing factors (covariates). Two of these used propensity score matching, a technique that pairs patients with similar characteristics so groups can be compared more fairly. However, two studies limited their adjusted modelling to men. Female sexual outcomes were left out of the multivariable analyses in those studies, again without a stated reason.

Data quality reporting was also thin. Only six studies reported response rates, and only one reported the filling rate for the sexual function questionnaires. For studies with several follow-up points, no study reported response rates at each individual assessment. None of the studies described how they handled missing questionnaire data — for example, whether they used complete-case analysis or imputation (a statistical method for filling in gaps). This matters because low or unreported completion rates can bias results.

Eight studies placed greater reporting emphasis on male outcomes than female ones. A small female sample size was noted in 16 of the 25 studies. Two of those studies explicitly acknowledged that women were under-represented, and four reported reluctance among female participants to complete sexual function questionnaires.

Quality of the Evidence

The overall certainty of the evidence was low. Using the MINORS tool, most included observational studies were rated moderate quality, with several rated high and a number rated low. Scores ranged from 7 of 16 to 20 of 24.

The two randomised controlled trials were assessed with RoB 2. Both were judged to have "some concerns" for overall risk of bias. One had some concerns only in how the outcome was measured. The other had some concerns in both deviations from the intended intervention and outcome measurement.

Clinical Implications: What This Means for Patients

The central message is that current survivorship evidence reflects male sexual outcomes far more than female ones. This leaves patients and clinicians with an incomplete picture of what women can expect after rectal cancer treatment.

Men's outcomes were reported most consistently, particularly erectile and ejaculatory function. Women's outcomes were often reduced to a single overall score, hiding which specific problems were occurring. When women were excluded from adjusted analyses, researchers could not tell how factors like age, treatment type or stoma status affected female sexual health.

This gap sits awkwardly against official guidance. The NCCN, ASCO and Macmillan Cancer Support all advocate proactive, routine and inclusive assessment of sexual health during survivorship care. The review suggests practice has not caught up with that advice.

The authors also note that sexual wellbeing is often a multifactorial late effect of cancer treatment. It may be overlooked in routine follow-up, and patients may be reluctant to raise concerns themselves. That combination means problems can go unaddressed for years.

Limitations: What the Study Could Not Prove

Several limitations temper the findings. First, the studies differed so much in design, questionnaires and timing that the researchers could not pool the data into a single combined result. All conclusions rest on patterns across studies rather than on one precise estimate.

Second, most included studies were observational. Only two were randomised controlled trials, and both carried some concerns for bias. Several observational studies scored low on the MINORS quality tool.

Third, follow-up varied enormously, from a few weeks to 4 years. Only 12 months after surgery was predefined as adequate, so many studies fell short of that benchmark.

Fourth, reporting of participation was weak. Few studies gave response rates, virtually none gave questionnaire completion rates at each time point, and none explained how missing data were handled.

Fifth, important context was rarely captured. Sexual activity status, sexual orientation, sexual practices and menopausal status were almost never recorded. Without that information, researchers cannot tell whose experiences are being described and whose are being missed.

Finally, the included studies reported outcomes by male or female classification rather than by gender identity. The reviewers therefore use "sex-based" terminology, and note that this limits what can be said about the experiences of transgender and non-binary patients.

Recommendations

The authors call for change at both research and clinical level. Their recommendations are:

1. Standardise reporting. Future studies should report sexual function outcomes consistently, using sex-specific methods and full domain-level detail rather than a single total score.
2. Develop a core outcome set. This is an agreed minimum set of outcomes that every future study should measure and report, so results can be compared and combined.
3. Include women properly. Female participants should not be dropped from assessment, analysis or statistical modelling. If a group is excluded, the reason must be stated.
4. Record contextual factors. Sexual activity, sexual orientation, sexual practices and menopausal status should be captured as standard.
5. Report data quality. Studies should state response and completion rates at every follow-up point and describe how missing data were handled.

For patients, the practical message is straightforward. Sexual difficulties after rectal cancer treatment are common and are recognised as a legitimate survivorship concern. If your care team does not raise the topic, you are entitled to raise it yourself. Ask about how your specific treatment — surgery, radiotherapy or chemotherapy — might affect sexual function, and ask what support is available.

Frequently Asked Questions

How common are sexual problems after rectal cancer treatment?

Sexual dysfunction is a well-recognised side effect of rectal cancer treatment and can substantially affect quality of life and emotional wellbeing. A review of 25 studies covering 4,071 patients found these problems are measured inconsistently, and that women are badly under-represented in the research, so the full picture for women remains incomplete.

Why are women under-represented in research on sexual problems after rectal cancer?

In a review of 25 studies, about two-thirds of participants (65.8%) were men. Five studies excluded women from sexual outcome analyses or statistical models without a stated reason, and eight studies emphasised male outcomes more. Some studies suggest women may be more reluctant than men to discuss sexual issues with their clinical team.

Which sexual problems are studied most after rectal cancer treatment?

Research has focused mainly on men, particularly erectile dysfunction (difficulty getting or keeping an erection) and ejaculatory dysfunction (problems with ejaculation). Female sexual problems are studied far less often; these include dyspareunia (pain during sex), vaginal dryness and reduced desire. A review of 25 studies found men's outcomes were reported most consistently.

What questionnaires measure sexual function after rectal cancer treatment?

Studies in a review of 25 studies used the International Index of Erectile Function (IIEF) for men and the Female Sexual Function Index (FSFI) for women. Thirteen studies used the short IIEF-5, which mainly assesses erectile function. For women, six studies used the FSFI-6, and others used the FSFI-9, IFSF, IFSI or full FSFI-19.

Does follow-up after rectal cancer treatment routinely address sexual health?

Routine follow-up often skips the topic entirely, and a report from the cancer charity Macmillan found sexual function problems are often forgotten or simply not discussed. International survivorship guidance recommends routine, multidomain assessment of sexual health, including emotional and social context, but a review of 25 studies suggests practice has not caught up with that advice.

What should I do if my care team does not raise sexual health after rectal cancer treatment?

Sexual difficulties after rectal cancer treatment are common and recognised as a legitimate survivorship concern. If your care team does not raise the topic, you are entitled to raise it yourself. Ask how your specific treatment — surgery, radiotherapy or chemotherapy — might affect sexual function, and ask what support is available.

What did the review recommend to improve research on sexual problems after rectal cancer?

The authors of a review of 25 studies called for standardised, sex-specific reporting with full domain-level detail rather than a single total score. They recommended developing a core outcome set, including women properly in assessment and analysis, recording contextual factors such as sexual activity and menopausal status, and reporting data quality at every follow-up point.

After rectal cancer treatment, when should a woman seek a second opinion about sexual problems that were never assessed?

Sexual difficulties after rectal cancer treatment are common and recognised as a legitimate survivorship concern, yet women's outcomes are often reduced to a single overall score, hiding which specific problems are occurring. Five studies excluded women from sexual outcome analyses or statistical models without stated reason, and female sexual outcomes were left out of adjusted analyses in others. If your care team does not raise the topic, you are entitled to raise it yourself. Ask how your specific treatment might affect sexual function and what support is available. Diagnostic Detectives Network provides independent expert second opinions.

Source Information

Original article title: Sexual dysfunction outcomes and reporting disparities after multimodal treatment for rectal cancer: A systematic review and narrative synthesis.

Authors: Lakshmanan V, Waterman J, Meggy A, Torkington J, Cornish JA.

Publication details: Colorectal Disease, 2026; volume 28, article e70599. DOI: 10.1111/codi.70599. Received 15 April 2026; revised 24 July 2026; accepted 12 August 2026. Published open access by John Wiley & Sons Ltd on behalf of the Association of Coloproctology of Great Britain and Ireland. Registration: PROSPERO CRD420251178502.

This patient-friendly article is based on peer-reviewed research.