The side effects of surgery for anal cancer depend on multiple factors, inclusive of the extent of the surgery and your health prior to undergoing the procedures. The typical treatment for anal cancer is chemoradiation. However, your clinician may recommend surgery instead of, or in addition to, chemoradiation. There are three types of surgeries that may be used depending on the stage of your cancer. They include local resection, abdominoperineal resection (APR) or ostomy.

On this page we discuss what you may expect immediately after surgery for anal cancer, the different types of surgery and the various side effects that you may experience after these procedures.

Please note that this page should not be used as a substitute for medical advice or information. Be sure to talk to your care team about what you are experiencing as they can make suggestions for management and adjustments to your treatment program.

Immediately after surgery

There is always the risk of pain after any type of surgery, and you may be able to manage this with medications if you feel they are needed. Pain should begin to lessen as your body heals.

Other risks include reactions to the anesthesia, damage to nearby organs, blood clots, bleeding and swelling or skin infections at the incision.

You may feel fatigued afterwards as your body begins to divert energy to the site of the surgery to help with the healing process. You may also experience appetite loss after surgery which can contribute to feelings of tiredness. This can lead to weight loss but as with most side effects directly related to surgery you will regain your appetite and any weight loss as your body heals itself over time.

local resection

A local resection only removes the tumor and a small area of normal, healthy tissue around it. The anal sphincter is not usually affected as this surgery is mostly reserved for smaller tumors on the outside of the anus. Bowel function tends to remain the same after a local resection, although please tell your doctor if you are experiencing pain or difficulty. You may also find that you experience some difficulty with urination after this procedure. If this occurs along with any other side effects, speak to your doctor.


An ostomy is a surgically created opening in the abdominal wall that is used for the removal of bodily waste, i.e. stool. There are different types of ostomies. For anal cancer, the most common ostomy is colostomy.

Ostomies can be temporary or permanent for anal cancer thrivers depending on the extent of injury done to the anus and rectum during anal cancer treatment. Some thrivers may only need an ostomy during chemoradiation treatment to help them avoid the pain of going to the bathroom, but can get the ostomy reversed once they have healed. Other ostomies are permanent because of one's treatment or physical circumstances prior to treatment. Please see our Side Effects of Radiation page for more information about why a provider may recommend an ostomy.

Individuals who undergo an APR must have permanent colostomies.

Seeing a Wound Ostomy and Continence Nurse (in the UK these are called Stoma Nurses) who can provide you expert care and advice on living with an ostomy can also be very helpful, for dietary issues and in general. These nurses may be more commonly referred to as a WOCN, although there are different certifications for different skill levels in the wound, ostomy and continence field. If you are in the US, locate your closest certified nurse here. If you are in the UK, be sure to speak to your care team and ask for referrals to a specialist nurse who can help you manage your ostomy.

An ostomy is often a frightening or distressing prospect for people, but many find that they adapt well over time. Remember that ostomies are used for many other conditions, not just anal cancer, so you are absolutely not alone in this! The American Cancer Society has a comprehensive guide to what to expect when you first get a colostomy, and how to manage and care for it in the long term. The United Ostomy Associations of America, Inc. (UOAA) also provides a wealth of information on their website. In the UK, the Colostomy Association is the leading source of information and help for individuals with ostomies.

abdominoperineal resection (APR)

An APR is a very extensive operation. It generally occurs after chemoradiation is unsuccessful in treating the primary tumor, but the cancer has not metastasized to other locations in the body. It involves removal of the anus and rectum, and sometimes some of the nearby groin lymph nodes as well. To assist in the removal of stool from the body, the end of colon is attached to a new opening in the abdomen called an ostomy. A small bag for collecting stool is attached to the opening and this is how the individual is able to evacuate stool from their body after the removal of their anus and rectum. For more information about ostomy side effects and management, see the ostomy section above.

After an APR, internal scar tissue may develop, which can cause organs and tissues to stick together. This can be painful and cause digestive issues such as bloating, cramping, nausea, vomiting and changes in bowel movements and regularity. Discuss with your medical team any side effects you experience after surgery.

Sexual side effects

There do not appear to be documented sexual side effects of local resection in either men or women, but please speak with your care team to confirm this. Be sure to ask if there is anything you should know about your sexual function before undergoing any type of surgery if this is a concern for you.

Men undergoing an APR may experience erectile dysfunction, and/or a lessening in their ability to achieve orgasm. Pleasure during orgasm may also become less intense. Finally, the nerves that control ejaculation can become damaged, which may lead to orgasms without semen, or 'dry' orgasms.

In women, an APR does not damage the nerves that control genital feeling and orgasm, although some women do notice vaginal dryness, especially if their ovaries have also been removed. Certain sexual positions may be painful or uncomfortable as the vagina becomes scarred to the tailbone. A couple may need to work together to find the most comfortable and enjoyable sexual positions.

Finally, the presence of an ostomy bag can have effects on body image and self-confidence in both men and women. The American Cancer Society provides some useful tips about managing the presence of an ostomy during sex. The UOAA also provides comprehensive advice about managing intimacy and ostomies for both men and women, as does the Colostomy Association in the UK.

Please speak to your surgical team about ways to minimize your sexual side effects. They may also be able to recommend sexual therapy or counselling, which can help thrivers manage sexual changes after surgery for anal cancer. 

Dietary changes and Bowel Issues

Any needed changes to your diet will depend on what sort of surgery you have had. If your anus and rectum have been removed, adjustments to your regular diet may be needed. A regular, balanced diet is recommended for individuals with colostomies, just as it is recommended for individuals without them!

If part of your bowel has been removed, your stools may become more watery as your body is no longer able to absorb as much water. Many thrivers have found that sanitary pads or adult diapers prove very useful during this time, not only to help manage any accidents, but also to provide peace of mind.

Foods that cause gas may be problematic if you have a colostomy, and it will probably take a little experimentation to discover what works with your system and what does not. Remember that sometimes the issue may not be with the food itself, but with the way it has been prepared, such as with added fat, for example. Gas-causing foods typically include:

  • High fiber fruit and vegetables, particularly raw.
  • Onions and cabbage.
  • Carbonated drinks, including beer.
  • Rich/fatty food.

If you are having issues, your doctor can help direct you to a dietician who can provide further help and guidance for your diet. Keeping a food diary before your visit, including how certain foods make you feel or any digestive issues you are having and their timing, can help maximize your time with the dietician. You may notice a pattern emerge around certain foods and make adjustments to your diet to help you feel better.

There are no foods that are truly off limits, and it’s important for you to focus on what works best for your body, and what makes you feel good or bad. Also, it’s common to find that a food that works well for you initially can cause problems further down the road, or vice versa. If a food is causing you trouble, try going without it for a few months and then trying again later if you feel up for it.

The UOAA and Colostomy Association both provide helpful guides to healthy eating for those with ostomies.

Looking for someone to talk to about your anal cancer diagnosis? We are here to help. The Peer to Peer Support Program is a free service provided by the Anal Cancer Foundation that matches anal cancer thrivers (our word for survivors) and caregivers with thriver volunteers and caregiver volunteers.