What has gone wrong?
It should be clear from the tests that you have had what disease there is in your rectum. The most common disease is a bowel cancer. This looks like a warty swelling or an ulcer inside the rectum. It may be narrowing or blocking the rectum.
The tests also show what type of bowel cancer it is, exactly where it is, how big it is, whether it is free from the surrounding tissues and whether there are any signs of spread elsewhere in the body.
There are also more rare causes, such as inflammatory bowel disease, which has not responded to treatment, or changes in the lining of the rectum that may turn into cancer if left, called pre-cancerous changes.
The aim of the operation
The aim is to remove the diseased part of your rectum together with your anus. Nearby lymph glands are also taken out for examination to check for any spread of the disease. We do the operation using 2 incisions. One is in the abdomen to free off the rectum from above. The other is in the perineum to free off the lower rectum and anus.
Both wounds are made at the same time; this is called an abdomino-perineal excision. We also make the colostomy at the same time.
The operation will get rid of the bleeding, loose motions, and mucus. We remove enough rectum, anus and other tissue to minimise the chance of any cancer coming back.
The operation should reduce the chance of a cancer spreading elsewhere in the body. Extra treatment with radiotherapy or chemotherapy may be helpful for this. The benefits of the operation should easily outweigh the disadvantages of having a colostomy.
Are there any alternatives?
Because we remove the rectum and anus, the remaining lower bowel cannot be stitched to the skin wound in the perineum, as you would not be able to control the motions. There would be no sphincter to control the opening. There are no devices at present that can take the place of the sphincter muscle, although there are ongoing trials. It may take several years to find out if this is a safe and reliable technique. One such device is the Acticon Neosphincter Anal Prosthesis. You can find out more details at www.clinicaltrials.gov. The National Institute for Clinical Excellence (NICE) issued guidance on artificial anal sphincter implantation in June 2004 (see www.nice.org.uk).
If we remove the rectum, but not the anus, joining the remaining lower bowel to the back passage may still not give you control of your motions. There would also be a higher risk of the cancer coming back.
If the cancer is high enough in the rectum the surgeon may suggest attempting to remove it, leaving the anus in place. S/he could then join the lower bowel to the anus; this operation is called an anterior resection of rectum. If, at operation, the cancer were found to be too low for this, then the surgeon would have to go ahead and remove the anus.
Simple trimming of the cancer with an electric cautery or a laser may give good relief from symptoms in a person who is not fit enough for major surgery. It may be possible to place a metal tube, called a stent, across a cancer that is obstructing the colon. Often, having radiotherapy or chemotherapy before or after the operation would be helpful in this case.
Sometimes the upper part of the operation can be done using keyhole surgery, called laparoscopic surgery. This would mean four or more one-inch long cuts in the abdomen instead of one long one. You should discuss the various options with your surgeon.
What if you do nothing?
If you do nothing your bowel symptoms will get worse. The cancer may completely block the rectum. The cancer may spread into other parts of the pelvis, such as the bladder or vagina. It may press on the ureters, stopping the urine flow or on the veins taking blood from the legs, causing the legs to swell. It may spread to the rest of the body.
Author: Mr Michael Edwards FRCSEng FRCSEd. Consultant general surgeon.
© Dumas Ltd 2006