Abdominoperineal Resection (APR)

What is an abdominoperineal resection?

An abdominoperineal resection (APR) is an operation that removes the lower part of the large bowel (the sigmoid colon), the entire rectum, the anus, and the muscles that control the back passage (the anal sphincters). Because those muscles are removed, it is not possible to restore the normal route for bowel movements. Instead, the end of the bowel is brought out through a small opening in your tummy wall — this is called a permanent end colostomy. Stools pass into a discreet bag that sits flat against your skin.

We want to be honest with you: this is a big change, and it takes time to adjust. But APR is only recommended when it is the operation that gives you the best chance of clearing the cancer safely. Surgical techniques, radiotherapy, and cancer treatments have improved enormously — APR is now reserved only for situations where keeping the back passage would mean leaving cancer behind, or where the muscles are already so damaged that keeping them would not give you useful bowel control anyway.

Mr Nguyen uses a modern approach called extralevator APR (ELAPR) — a slightly wider removal that includes the surrounding muscles, which gives a better margin around very low tumours and reduces the chance of the cancer coming back. The abdominal part of the operation is done through keyhole incisions using a laparoscopic or robotic approach wherever possible.

Who needs this operation?

• Very low rectal cancer — where the tumour is sitting right at or very close to the anal sphincters, meaning there is no room to cut safely around it while keeping the back passage. Trying to preserve the sphincters in this situation would risk leaving cancer behind
• Locally advanced rectal cancer — where the cancer has grown into the sphincter muscles or the levator muscles (the sling of muscle around the lower pelvis)
• Anal canal cancer — when the standard first treatment (combined chemotherapy and radiotherapy) has not fully cleared the cancer, and a salvage operation is needed
• Rectal cancer in someone whose sphincters are already not working well — in this situation, keeping the back passage would result in severe leakage of stool, which most people find far more disruptive than a well-managed colostomy
• Rectal cancer that has come back in the pelvis and cannot be treated in another way

How is it performed?

APR is a two-part operation done under general anaesthesia — you will be completely asleep throughout. It usually takes 3–5 hours. You will not feel anything during the surgery.

Abdominal part (keyhole surgery)

Through several small keyhole incisions on your tummy, Mr Nguyen carefully separates the bowel from the surrounding structures. The rectum and its surrounding tissue (which contains the lymph nodes) are removed in a single package — this precise technique, called total mesorectal excision (TME), helps ensure a clear margin around the cancer. Throughout this process, Mr Nguyen works carefully to protect the nearby nerves that control your bladder and sexual function. The end of the bowel is then brought out through a small opening on the left side of your tummy to form your permanent colostomy.

Perineal part (from below)

While you are still asleep, a second set of incisions is made around the back passage. The anus, sphincter muscles, and the surrounding tissue are removed in one piece from below — together with what was removed from above, this forms a single complete specimen. The wound in the perineum (the area between your legs) is then carefully stitched closed. If you have had radiotherapy, the tissues can be less robust, and a plastic surgeon may help close the gap using a small flap of nearby muscle or skin.

Your new colostomy

Before your operation, a stomal therapy nurse will visit you and mark a spot on your tummy for the colostomy — the position is chosen carefully to suit your body shape and your lifestyle. The stoma (the opening on your tummy) usually starts working within 2–4 days after the operation. The stomal therapy nurse will be with you every step of the way to teach you how to manage it confidently before you go home.

Before the operation

• MRI scan of your pelvis and a CT scan to carefully plan the operation and confirm your cancer staging; you will also need to have completed any chemotherapy-radiotherapy treatment and had enough recovery time before surgery
• A visit with a stomal therapy nurse before the operation to mark the best spot on your tummy for your colostomy — the position matters and is chosen to suit your body and your day-to-day life
• Stoma education — before you go into hospital, you will be shown exactly how a colostomy bag works, how to change it, and how to care for your skin. By the time you go home, you will feel confident managing it yourself
• Referral to a pelvic floor physiotherapist if time allows — to help your perineal area recover after the operation
• Emotional preparation — this is a significant operation, and it is completely normal to feel frightened or overwhelmed. Mr Nguyen strongly encourages you to ask every question you have. If it would help, we can connect you with a psychologist or a peer support group of people who have lived through the same experience and adjusted well

What to expect on the day

• You will be admitted in the morning. A needle will be placed in a vein in your arm (an IV line) and you will be given antibiotics before the operation to reduce infection risk, along with compression stockings to protect against blood clots.
• You will be completely asleep under general anaesthesia — you will not feel anything. The operation takes approximately 3–5 hours, and you will spend time in the recovery area afterwards while you wake up gradually, with nurses watching over you the whole time.
• You will wake up with a urinary catheter (a thin tube draining your bladder — you will not feel it). This is usually removed on day 3–5, once your bladder is working normally again.
• Pain is managed carefully from the start — often using an epidural (pain-numbing medication fed gently into your back) or a PCA (a pump that lets you give yourself small, safe doses of pain relief by pressing a button). By day 2–3, you will usually be able to manage with tablets alone.
• Your colostomy usually starts working within 2–4 days — this is completely normal and nothing to worry about. A stomal therapy nurse will visit you every day in hospital to support you and teach you how to manage it step by step.
• The wound in the perineum (the area between your legs where the back passage was) is checked and dressed regularly. There may be a small drain tube in place for the first day or two — it is just collecting any fluid from the healing area.
• Getting up and moving, even just to sit in a chair on the first day, is strongly encouraged — early movement genuinely speeds up your recovery and reduces the risk of complications.

Recovery

In hospital (5–8 days): Recovery from an APR takes a little longer than some other bowel operations, largely because of the perineal wound (the wound where the back passage was). Your diet builds up gradually from clear fluids over the first 3–4 days. Before you go home, the stomal therapy nurses will make sure you feel confident managing your colostomy on your own — you will not be sent home until you feel ready.

The perineal wound: This wound heals from the inside out, which takes time — typically 4–8 weeks. In patients who have had radiotherapy, healing can take longer as radiation affects the tissues' ability to repair. A district nurse or wound care clinic will help you manage this at home; you will not be dealing with it alone.

At home:

• Weeks 1–4: Focus on rest, wound care, and getting comfortable with your colostomy. The stomal therapy nurse will continue to see you in clinic or through home visits. Avoid sitting for long periods, as this puts pressure on the perineal wound — use a cushion or change position regularly.
• Weeks 4–8: Most people feel gradually more energetic and start returning to light daily activities. Your colostomy output becomes more predictable week by week. You can usually return to driving around 4–6 weeks after surgery, once you are comfortable and off opioid pain medicine.
• Weeks 6–12: You can return to most normal activities and light work. Avoid lifting anything heavier than 5 kg for at least 6 weeks — longer if your perineal wound is still healing. Your body needs this time to rebuild properly inside.
• Living with a colostomy long-term: The vast majority of people adjust far better than they expect. Colostomy bags today are discreet, reliable, and barely noticeable under clothing. Small dietary tweaks (such as reducing certain gas-forming foods), staying well hydrated, and choosing the right appliance for your body make a real difference. Most people go on to travel, swim, exercise, and enjoy sexual activity again. Your stomal therapy team is an ongoing resource — you can call on them any time you have questions.
• A post-operative review with Mr Nguyen is routinely arranged 2–6 weeks following your procedure, with timing depending on the type of operation — this review is provided at no charge

Your pathology results — the detailed laboratory report on the tissue removed during your operation — are usually available within 2 weeks and will be discussed at your follow-up appointment. Mr Nguyen will then arrange regular ongoing check-ups, at least every six months, including clinic visits, imaging, and blood tests. If further treatment such as chemotherapy is recommended, you will be referred to a medical oncologist who will talk through your options.

Risks and complications

We want to be honest with you about the risks of this operation — because facing them clearly is part of being well-prepared. APR is a major operation, and it carries more specific risks than some others. Please know that Mr Nguyen and the team take many active steps to minimise each of them, and that most people come through this surgery and go on to live full lives.

The perineal wound

• Wound healing problems — the wound where your back passage was can be slow to heal. Delayed healing, wound breakdown, or infection affects roughly 15–30 in 100 patients, and is more common in those who have had radiotherapy — because radiation reduces the tissues' ability to heal. This is the most common complication of APR. It sounds alarming, but it is very manageable with good wound care support at home, and it does resolve.
• Perineal hernia — over time, bowel or pelvic tissue can push into the space left by the operation (the perineal defect), forming a hernia. This may eventually need a surgical repair. Mr Nguyen uses techniques to reduce this risk during the initial operation where possible.

Bladder and sexual function

• Difficulty emptying the bladder — the nerves that control your bladder run very close to the area being operated on. Temporary difficulty emptying the bladder fully is relatively common; most patients recover normal bladder function over the following weeks. The urinary catheter is kept in place until the bladder is working well.
• Changes in sexual function — in men, this may include difficulty achieving an erection (erectile dysfunction) or retrograde ejaculation (semen directed backwards into the bladder rather than forwards). In women, changes in sensation or discomfort during sex (dyspareunia) may occur. These effects are more common after APR than after some other pelvic operations, because of the extent of the surgery in the pelvis. Mr Nguyen uses careful nerve-sparing technique throughout, and can discuss this with you and your partner in detail before the operation. Support and treatment options are available.
• Phantom rectum sensation — some people experience a feeling of needing to go to the toilet, or a sensation of pressure or fullness where the rectum used to be, even though it has been removed. This is a known neurological effect — your brain simply hasn't fully "updated" yet. It is not painful, and in almost all cases it fades significantly over the first few months.

Colostomy-related

• Parastomal hernia — a hernia that develops around the stoma opening over time, as the bowel pushes through the weakness in the abdominal wall. This affects roughly 30–50 in 100 patients with a permanent colostomy, usually over years rather than immediately. It can often be managed with a supportive belt or appliance; surgical repair is available if needed. See parastomal hernia repair.
• Colostomy prolapse or retraction — occasionally the stoma protrudes further out than expected (prolapse) or pulls back below the skin (retraction). Both can usually be managed with the right appliance; occasionally a small corrective procedure is needed.
• Skin problems around the stoma — irritation or soreness is common early on, particularly if the bag does not fit perfectly. Your stomal therapy nurse will help you find the right appliance and technique — this is almost always fixable.

General surgical risks

• Blood clots (DVT or PE), bleeding, chest infection, and small bowel obstruction from scar tissue are all possible after any major abdominal operation. You will be given compression stockings, blood-thinning injections, and physiotherapy breathing exercises to reduce these risks. The team monitors you closely for any early signs of these complications throughout your stay.

Frequently asked questions

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