Anterior Resection


This information is to be used as a guide in conjunction with your surgical consultation. Anterior resection is the operation to remove the lower colon (sigmoid) and upper rectum. Indications include colon and rectal cancer and benign conditions such as diverticulitis and ulcerative colitis.


During the operation, the diseased area of bowel and a length of normal bowel either side of it are removed. This involves taking the blood vessels and lymph nodes to that part of the bowel; the two ends of healthy bowel are then joined by stitching or stapling together (anastomosis).


If a rectal lesion is very low (close to the anus) the operation is called Ultra-low anterior resection (ULAR) and may also include formation of a Colonic J pouch (CJP) from the healthy colon, which acts as a reservoir to hold the stool (similar to the rectum) allowing better bowel function.


It may also be necessary to have a temporary stoma to divert stools away from the surgical join in the bowel whilst it heals (this would be discussed at your surgical consultation if relevant).


A stoma is an opening of the bowel onto the abdomen; stools that come through the stoma are collected in a bag that covers it. A Stomal therapy nurse will discuss this with you beforehand and also mark a suitable site on your abdomen in case a stoma is necessary.


Should a stoma be necessary, a second operation to reverse the stoma may be performed so the stools pass through your anus in the normal way again.


There are two ways that surgery can be performed.

‘Open’ (Laparotomy) where the surgeon makes a larger incision in your abdomen to remove the affected area of bowel and ‘Laparoscopic’ (Keyhole), where a number of small incisions allow manipulation of specialist instruments guided by a camera. Laparoscopic technique is used whenever possible.


Recognised benefits of keyhole (Laparoscopic) surgery include:

  • Shorter recovery time and earlier discharge
  • Reduced post-operative pain
  • Minimal scarring
  • Early return of bowel function


The approach used often depends on your general health and previous medical and surgical history. It is important to note that if you are to undergo laparoscopic surgery, sometimes operations may begin as laparoscopic but then convert to an open procedure for technical reasons.


A bowel cleansing preparation to clear the bowel is required for anterior resection. Discharge from hospital is usually 4-5 days post operatively.



What risks are there in having this procedure?


There are risks associated with any abdominal operation, pre-operative assessment of heart and lung conditions are made, as well as any coexisting medical conditions. During the hospital admission patients wear compression stockings and are given small injections to prevent thrombosis (blood clots).


Bleeding- is rare in this type of surgery, but if significant a transfusion may be required.


Anastomotic leak - sometimes the anastomosis (join in the bowel) leaks. Treatment with antibiotics and resting the bowel are generally enough, however this may be a serious complication which needs further surgery and formation of a stoma.


Nerve damage - the operation is very close to the muscle in the anus (anal sphincter). This may become bruised causing a loss of sensation, which occasionally leads to slight incontinence of wind and/or stools in the early days after your operation.  The operation is also very close to the bladder and nerves responsible for sexual function. Bladder and sexual function may be disturbed although the risk is small and often temporary.


Ileus (paralysis of the bowel) - Sometimes the bowel is slow to start working after surgery, which causes vomiting and delays you from eating and drinking normally in hospital. If this happens you will need a period of bowel rest with continued intravenous fluids for hydration and sometimes a tube passed via the nose to the stomach (nasogastric tube).


Bowel obstruction – When the bowel doesn’t start working properly there may be a kink, twist or adhesion causing a blockage, this is known as obstruction. Patients may develop colicky abdominal pains, abdominal distension and vomiting, if this happen you will need a period of bowel rest with continued intravenous fluids and sometimes a tube passed via the nose to the stomach (nasogastric tube). In most cases the obstruction settles spontaneously occasionally an operation is required to relieve the blockage.


Wound infection can occur in any form of intestinal surgery, open or laparoscopic; wound infections rarely cause serious problems but may require treatment with antibiotics.



What are the benefits of this procedure?


The operation aims to remove the diseased bowel. In most cases this will give you the best chance of a cure or significant improvement in your bowel problems.



What are the alternatives?

(This section relevant only to surgery for bowel cancer)


If the operation has been recommended by your surgeon as the best treatment, not having surgery may lead to bleeding, discharge, pain and possibly a complete blockage of the bowel.  If you choose not to have surgery, radiotherapy and/or chemotherapy may be offered. This may control your symptoms but will not cure the disease.  Occasionally it is possible to remove a rectal cancer using surgery directly from within the anus. This type of surgery is only suitable for a small number of patients. Another option is a stent (an internal splint in the bowel) this is inserted through the anus into the rectum to keep the bowel open; this may help with symptoms but will not cure the disease your surgeon will discuss these options if appropriate.



What are the consequences of this operation?


After any major bowel operation the function of the bowel can change. You may experience:

  • Difficulty controlling wind.
  • Urgency or difficulty with bowel control.
  • Loose stools or diarrhoea.

For most people, these improve with time but can take many months to settle down. You may need to have a low fibre diet for an extended period and medication to help control your bowels.



Preparing for your operation        


A bowel cleansing prep (usually Moviprep brand) is taken as instructed to clear the large bowel.


You will need to fast for 6 hours prior to the operation for a general anaesthetic.


Pain relief will be discussed with you by your anaesthetist, you may be given analgesia through an epidural (tube in your back) or through a drip in your arm in the form of a PCA (patient controlled analgesia), this means you control the amount of analgesia you require.


Your operation will take approximately 2 hours.



After your operation


  • Patients will have an intravenous drip which remains in place until a normal oral fluid intake is resumed.
  • A catheter (tube inserted to drain the bladder) is normally kept in place for 1 or more days.
  • Pain relief can be given intravenously, usually with a PCA (patient controlled analgesia) or via an epidural and oral medication; your anaesthetist will discuss this with you.
  • Occasionally an abdominal drain is used (small tube passing through the abdominal wall).


Over a period of two to three days many or all of these tubes will be removed. People recover from surgery at different rates, the average stay in hospital is 4 to 5 days but you may need to stay in longer.


A few days following your surgery a report from histopathology (examination under the microscope) on the bowel and tissue removed during the operation will be sent to your surgeon.


Depending on the results, further treatment may be offered, the details of which will be discussed with you. If there is an option for further treatment such as chemotherapy: a consultation with a medical oncologist (cancer specialist).  Relevant only to operations for bowel cancer 



Discharge home


Following your operation you may feel tired and weak. Full recovery may take several weeks. Many people report that they feel better sooner at home.


You may find that you tire easily, try to alternate light activity with periods of rest. A short rest in the day is often helpful during the first two to three weeks after being home.


Start with some frequent gentle exercise, like walking around your home or garden.


For the first six weeks do not lift anything heavy such as shopping or wet washing, or do anything strenuous like digging the garden or mowing the lawn.


You should have a low residue diet for the first week or two, avoid insoluble fibre such as nuts, skins, seeds, grains and high fibre cereals, start with smaller light meals, as your bowel function improves and you feel comfortable after eating you can gradually introduce more fibre such as cooked vegetables, salads and fruits.


Your abdominal wounds will be covered with waterproof dressings which can be removed 5-7 days post operation, you may shower as normal.


Other specific instructions may be given to you on discharge from hospital.


Don’t drive until you are quite comfortable, usually a minimum of 2 weeks post operatively.


Recovery times vary. As a guide, 2 – 6 weeks sick leave may be required.    



Possible longer-term complications of abdominal surgery


Incisional hernia: Presents as bulge in abdominal wall close to the wound site. This occurs in 10-15% of abdominal wounds and usually appears within the first year following surgery but can be later. They maybe small with minimal symptoms but can sometimes cause pain/discomfort or increase in size over time.


Adhesions (scar tissue): Scar tissue that forms between tissues and organs after any operation. Typically, scar tissue begins to form within the first few days of surgery, but they may not produce symptoms for months or years. In some cases these can cause complications such as pain, affect the activity of the bowel leading to hospital admission or further surgery.


Pain: Acute postoperative pain usually settles within a couple of weeks with most patients being quite comfortable. Some patients may experience residual pain that may require further review with Dr Meade; options for treatment are based on understanding the pain mechanisms involved.