Surgery is the main treatment for tumors of the bowel. Usually, the tumor and a length of normal bowel on either side of the tumor (as well as nearby lymph nodes) are removed. The healthy parts of the bowel are then stitched or stapled together (anastomosis). If the doctor is not able to join the bowel back together, an opening (stoma) will be made on the outside of the body for waste to pass out of the body. This is called a colostomy. A colostomy is made to allow waste to pass through an opening in the abdominal wall. Sometimes, a temporary colostomy is needed until the joined bowel has healed, and then it can be put back. This is done by further surgery. However, in some cases, the colostomy is permanent, which means it can never be put back, and there will always be an opening on the skin for bowel waste to pass through. A number of different surgical procedures are used depending on where the tumor is. These include:

• Right hemicolectomy: Removal of the last part of the small bowel, the caecum, ascending colon and a small part of the transverse colon.
• Left hemicolectomy: Removal of the descending colon and sigmoid colon.
• Sigmoid colectomy: Removal of the sigmoid colon and nearby large bowel.

A number of different surgical procedures are available to treat tumors of the back passage, the choice depending on where the tumor is and how far it has spread:

• Low anterior resection (LAR): Used for most tumors of the back passage, except when the tumor is very close to the anal muscles (sphincter). The bowel and the back passage are joined together so that the back passage is spared.
• Abdomino-perineal resection (APR): This is done when the tumor is in the lowest part of the back passage. The back passage and the opening to the back passage are removed and the area is stitched up and will remain permanently closed.

Removal of the diseased bowel is the first treatment for a tumor of the bowel. The goal of the surgery is to give you the best chance of cure through total removal of the tumor. However, your recovery depends how far the disease has spread at the time of your operation. Surgery can also be used as a measure to ease symptoms.
 
 

• Leakage of bowel fluid inside the abdomen: Leakage of bowel fluid at the site where the bowel was stitched or stapled back together. Further surgery may be required.
• Ileus: The bowel is paralyzed leading to abdominal bloating, and vomiting. The treatment is to deflate the bowel with suction, using a tube (nasogastric tube) put up the nose, down the back of the throat and into the stomach or bowel.
• Wound infection: The wound may become infected. This may be treated with antibiotics. These may be given by a drip into a vein or by mouth. The wound may need to be opened to drain.
• Urinary tract infection: Germs enter the tube leading to the bladder and cause inflammation and infection. Mild cases may clear up without treatment. Usually antibiotics are used to treat the infection.
• Possible stoma problems:
  • Loss of blood supply: The blood supply to the stoma may fail and cause damage to the bowel. This may need further surgery.
  • Stoma prolapse: Stoma prolapse occurs when some of the bowel sticks out too far past the skin. For minor prolapses, no treatment is needed. For more serious cases, more surgery may be needed.
  • Postoperative bleeding: Bleeding inside the abdomen may occur. The wound drain may measure this. A blood transfusion may be needed to replace lost blood. Sometimes more surgery is needed to stop the bleeding.
• Damage to the ureter (tube from kidney to bladder): Rarely, during surgery, the ureter, which brings urine from the kidney to the bladder, may be damaged. This may need more surgery.
• Bladder may not empty properly or may empty without warning: A urinary bladder problem where there is abnormal emptying of the bladder. It may empty without warning or may not empty at all.
• Sexual problems: Men may be unable to get an erection or keep an erection. It may also mean that they cannot ejaculate. In women it may cause pain during or after intercourse. For both men and women, time may improve the condition. Treatment for men may include counseling and medication. For women, counseling and use of water-soluble lubricants during intercourse may help.
• Bowel blockage: Adhesions (bands of scar tissue) may develop inside the abdomen and the bowel may block. This is a short term and a long term complication. This may need more surgery.
• Change in bowel habits: Bowel habits will change. Stools may be looser, smaller and more frequent. There may be some leakage of stools particularly at night is depending on the type of surgery. In most people, this improves with time, without further treatment.
• Increased risk in obese patients and smokers: The risk of wound infection, chest infection, heart and lung complications and thrombosis may increase in obese patients and smokers.

• If you are taking any blood-thinning medication/anticoagulant, please let your doctor know as some may need to be stopped before you travel for the procedure.
• Travelers to Thailand should plan to stay in the country for at least two to three weeks or for the entire duration of treatment.
• If you plan to return home after the procedure, please speak to your doctor before making travel arrangements.
• During your follow-up appointment your medical team will assess your health and your incision and you will receive documents detailing your medical and treatment history and your "Fit to Fly" certificate (if needed).

The success of the procedure depends on a number of factors. Please discuss the likelihood of success with your doctor before the procedure.
 
What if the procedure is not performed?
Symptoms including pain and bleeding may become worse and your bowel may completely block or burst. Without surgery, the disease may spread to other areas of your body.
 

Radiation therapy has been used for some people as the main treatment for rectal tumors but is not normally used in colon tumors.

Radiation therapy is not as effective as surgery for patients who could normally be treated by bowel removal. Chemotherapy (the use of drugs to treat tumor) is usually used together with surgical removal and may not be offered as the only treatment.