Why me?

Colorectal cancer or cancer of the large bowel, comprising the colon and the rectum, is common in New Zealand. (The lifetime risk is about 5-6% for the average New Zealander). In the majority of people with bowel cancer here is no single definable reason for the condition to develop however most cancers develop in pre-existing benign polyps that of themselves do not cause symptoms. In about 5% of patients there is a dominant inherited gene that confers a very high chance of developing the disease. In a further 20% of patients there is a family history of the disease.

What tests are conducted before surgery?

A colonoscopy is usually performed to diagnose a bowel cancer and a biopsy of the tumour is taken at the time to confirm the nature of the lesion. It is important to make sure that there are no other polyps or tumours elsewhere in the colon prior to surgery. If this is not possible then a colonoscopy is required after surgery.

To assess the clinical stage of the tumour (how advanced it is) a CT scan of the chest, abdomen and pelvis is required. A blood test for a CEA (tumour marker) is taken for baseline estimation.

What does Surgery involve?

Surgery is performed under a general anaesthetic with bowel preparation in selected cases. Some patients and their tumours are suitable for laparoscopic assisted (keyhole) surgery and some require conventional open surgery. In both approaches the diseased bowel and associated lymph nodes are removed and the two healthy ends of the bowel are rejoined. A urinary catheter is usually removed the day after surgery. A nasogatric tube is not routinely used. A hospital stay of between four and six days is usual. A colostomy or ileostomy (stoma bag) is rarely required after surgery for colon cancer.

What can I expect after surgery?

Some abdominal pain is usual after major abdominal surgery but a keyhole technique and and advanced analgesia will minimise this. Pain relief is achieved with wound catheters, a self-administered opiate pump (PCA of morphine or fentanyl) or an epidural. Bowel function usually returns 2-5 days after surgery but you may resume drinking on return to the ward. Your nurse will get you out of bed on the first post-operative day. Regular use of chewing gum after surgery can hasten return of bowel function.

A blood thinning injection is given daily and compression stockings will be fitted to reduce the risk of developing blood clots.

What can I expect when I get home?

A regular bowel habit takes some weeks to establish itself after colonic surgery. Bowel motions are usually more frequent than normal during this period of adjustment.

All patients suffer from “post-operative fatigue syndrome” after surgery. In this period of four to six weeks you will feel tired after seemingly minimal exertion, either physical or mental. This is part of the normal recovery process and your energy levels will return to normal after a period of some weeks.

What are the possible complications of surgery for colon cancer?

The most important complication of any form of bowel surgery is a failure of the two ends of the bowel to heal a condition known as “anastomotic leakage”. This complication happens in about 2% of cases and requires a return to the operating theatre and a temporary stoma bag to deal with the problem.  A period in intensive care will invariably be required if this complication occurs. This complication has a mortality risk.  Wound, intra-abdominal and chest infections may also complicate colon surgery. Blood clots in the legs and the lung may also occur after colon surgery. If there is a history of heart disease we will discuss your surgery with your cardiologist and anaesthetist. Measures are routinely employed to reduce the risk of all these complications but the risk cannot be totally eliminated.

Treatment options and follow up treatment after surgery

Surgery remains the mainstay of the treatment of bowel cancer. Surgery alone cures 50% of all bowel cancers and over 90% of early cases. There is no evidence that “letting in the air” results in tumour progression.  Detailed prognostic information will be available when the full pathology report is issued 10-14 days after surgery. Chemotherapy is used in two different ways in bowel cancer. “Adjuvant” chemotherapy is employed to improve the results of surgery in higher risk cases (usually with positive lymph nodes) even though there is no residual disease that can be seen on scans or at completion of surgery.

liver resection, lung resection and / or chemotherapy are treatment options if there are secondary deposits. Currently in Wellington chemotherapy is delivered at the Wellington Blood and Cancer Center (Wellington Public Hospital) or at the private medical oncology unit (Bowen Icon Cancer Centre) at Bowen Hospital.

More information needed?

“Informed consent for surgery is a process not a piece of paper”! The expected outcome of surgery (return to health) must be weighed against the small chance of an adverse outcome or complication. If you require more information on any aspect of your condition or proposed treatment please make an appointment to discuss your concerns. Your general practitioner, medical or radiation oncologist or the cancer society will also provide information and or support.

Useful websites






Wellington Blood and Cancer Centre                    04 806 2043

Bowen Icon Cancer Centre                                      04 896 0200

Wellington Hospital                                                 04 385 5999

Southern Cross Specialist Centre                           04 910 2178

Bowen Gastroenterology                                         04 479 8261

Cancer Society of NZ, Wellington division           04 389 8421

Cancer Society of NZ, Kapiti office                        04 298 8514

Cancer Society of NZ, Wairarapa office                 06 378 8039