The short answer
Pelvic radiation can narrow and stiffen the vagina. The American Cancer Society says dilators help keep it open and more flexible, and NCI says they can help prevent or reverse scarring. Your team teaches you when and how to use one.
Dilators help keep the vagina open and more flexible after pelvic radiation or surgery, according to the American Cancer Society.
ACS says a dilator can be used several times a week, and that your team will teach you when and how to start.
ACS says petroleum jelly and other oil-based products are not good choices for vaginal lubrication.
Pain is a reason to stop and ask your team, not to push harder.
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This page is for people who have been given a vaginal dilator after pelvic radiation or surgery. It explains why dilators are used. It shares what the NCI and the American Cancer Society (ACS) say about using them. It also says when to get help.
What a dilator is
A dilator is a smooth device. You put it into the vagina to keep it open and stretchy. ACS says it feels much like putting in a large tampon for a few minutes. Dilators come in various sizes. Many people are handed one with a leaflet and no conversation. This is the conversation.
Why it is recommended
Radiation to the pelvis changes vaginal tissue. NCI lists "vaginal stenosis," which means narrowing. It also lists "vaginal atrophy," where the muscles weaken and the walls become thin. And it lists vaginal itching, burning and inflammation. These can cause pain and discomfort during sex. Radiation can cause low estrogen levels, and so vaginal dryness. ACS adds that treatment can shorten or narrow the vagina. Its walls may also become less soft and flexible.
NCI says a dilator can help prevent or reverse scarring. This applies if radiation therapy or graft-versus-host disease has affected your vagina. (Graft-versus-host disease is a complication after a donor stem cell transplant.) ACS says dilators help keep your vagina open and more flexible after cancer treatment. It recommends them especially after pelvic radiation or surgery.
How they are typically used
ACS says you can use a dilator several times a week. This keeps scar tissue from making your vagina tight. It adds that you will be taught when to start and how to use it. Schedules vary between centers, so follow the instructions your own team gives you, not a number you found online.
Ask your team about the right size now and how you will know when to move up.
Lubricant
ACS recommends water-based lubricants with no perfumes, coloring, spermicide, herbal remedies or flavors. It says petroleum jelly, skin lotions and other oil-based lubricants are not good choices for vaginal lubrication. Ask your team which lubricant or moisturizer they suggest for you.
Discomfort and bleeding
Pain is a signal to stop and ask your team, not to push harder. ACS says light bleeding after sex can happen even if you do not have pain. It also says vaginal ulcers or open sores can develop in rare cases. These can take several months to heal after radiation therapy ends.
When to get help sooner
- Call your care team right away if bleeding soaks a pad, or if bleeding keeps going.
- Call your care team within a day or two if you find an open sore or ulcer inside the vagina, or if there is new discharge with an odor.
- Call your care team within a day or two if insertion hurts every single time, or you cannot use the dilator at all. That is the point to ask for a pelvic floor therapist, not to push harder or quietly give up.
Who to ask when it hurts or is not working
If it hurts, will not go in, or you have quietly stopped using it, ask your oncology team or nurse.
ACS says to ask your oncologist for a referral to a pelvic floor therapist. It notes that many cancer centers have them. ACS lists Kegel exercises, biofeedback and vaginal dilators among the treatments a therapist may use. ACS also says Kegel exercises teach you to control your pelvic floor and vaginal muscles. It quotes a specialist who says that without help the symptoms are unlikely to improve. They can get worse.
Tell your team about any changes in your sexual life or any new problems that come up. See also sexual health for women with cancer and pelvic floor rehabilitation after cancer treatment.
Sources
- National Cancer Institute (NCI): Sexual Health Issues in Women and Cancer Treatment
- American Cancer Society: Managing Sexual Side Effects as a Woman with Cancer
- American Cancer Society: How Radiation Therapy Can Affect Sex for Women
- American Cancer Society: How Pelvic Floor Therapy Can Help During Cancer
Common questions
Why has a dilator been recommended to me?
Radiation to the pelvis changes vaginal tissue. NCI lists vaginal stenosis, which means narrowing; vaginal atrophy, where the muscles weaken and the walls become thin; and vaginal itching, burning and inflammation, which can cause pain and discomfort during sex. Radiation can cause low estrogen levels and therefore dryness. NCI says dilators can help prevent or reverse scarring if radiation therapy or graft-versus-host disease has affected your vagina.
How often should I use it?
Follow the instructions your own team gives you, not a number you found online. The American Cancer Society says a dilator can be used several times a week to keep the vagina from getting tight from scar tissue, and that you will be taught when to start and how and when to use it.
How much discomfort is normal?
Ask your team what to expect and what to do if it hurts. Pain is a reason to stop and ask, not to push harder. If bleeding soaks a pad, call your care team right away. Light bleeding after sex can happen even without pain, according to ACS.
What if it hurts every time, or I cannot use it at all?
That is a clinical problem with clinical answers, not a reason to quietly stop. Ask your oncologist for a referral to a pelvic floor therapist. ACS says many cancer centers have them. Their treatments may include Kegel exercises, biofeedback and vaginal dilators.
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Written by: Cancer ExplainedSources last checked: 2026-10-02 what this meansLast updated: 2026-10-02Next planned review: 2027-01-28
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Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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