What is the Colon?
The colon of the large intestine is a 5 foot long organ in average adults. The right side of the colon absorbs one to 1.5 liters (quarts) of water daily from the food, liquid and digestive juices delivered to it from the small intestine. In the left side of the colon, bacteria grows digesting much of the remaining waste and turning it into stool (bowel movement). The stool is then delivered to the rectum for evacuation. The lining of the colon has rapidly multiplying cells which makes mucous constantly to lubricate the flow of colonic contents.
Approximately 150,000 Americans each year are diagnosed with adenocarcinoma of the colon (common colon cancer ). Approximately 1/3 will not survive five years with the disease. Colon cancer occurs most commonly in the sigmoid colon and the rectum (please see separate section on rectal cancer), and is next most commonly seen in the right or ascending colon and is least common in the transverse colon (the middle portion.) Adenocarinoma of the colon begins in the mucus secreting cells that line the large intestine. Ninety-five percent of the time it begins as a small bump or growth known as an adenomatous polyp or a tubulovillous adenoma. Approximately 24% of all adenomas if left untreated for 20 years will develop into a cancer. The larger the polyp the more likely it is to harbor at least early cancer.
What are the signs and symptoms of Colon Cancer?
The most common presenting sign is blood in the bowel movements, either red or dark blood seen in the toilet or the stool. So-called occult blood is found by testing the stool to see if there is evidence of digestive blood. Other symptoms may include narrowing in the size of the bowel movement, bloating, decrease in bowel movement or stool frequency, abdominal cramping, and weight loss. Anyone with a personal history of polyps or with a family history of colon cancer or colon polyps is at increased risk to develop colon cancer. Other risk factors include increasing age and obesity.
How is colon cancer diagnosed?
Most colon cancers are detected by colonoscopy and biopsy of suspicious growths via examination under the microscope by a pathologist. They may also be detected by various x-rays such as a CT scan or barium enema. Left-sided colon cancers may be detected by flexible sigmoidoscopy or by rigid proctoscopy.
Surgery for Colon Cancer
The type and extent of surgery for colon cancer depends largely on the location of the cancer. The goal is to remove not only the colon cancer, but a few centimeters of colon on either side of the tumor as well as the major artery or arteries which feed the area since lymph nodes are found along the arteries. Colon cancer tends to begin in the lining of the colon then go through the bowel wall, spread to lymph nodes and ultimately spread via intestinal veins to the liver. Rarely colon cancer will spread via the veins in to the lung.
In the hands of an experienced surgeon most colon resections can be done laparoscopically through 3-4 small incisions. The large incision will be made just large enough to remove the tumor and the bowel to send to the pathologist for examination. After this the ends of the bowel are reconstructed and the incision is closed.
Preoperative Evaluation and Surgical Preparation
Typically preoperative workup in a patient with known cancer of the colon and rectum includes a CAT scan to assess whether there the tumor migh have spread to the liver, which may require biopsy or even removal of that portion of the liver. In addition, the CAT scan can often detect any lymph nodes that are enlarged so they may be removed for pathologic examination to see if there is cancer within them.
Additionally, a CAT scan should tell the surgeon whether the cancer is close to or adherent to a structure which might need to be removed in part or in whole at the time of the surgery thus allowing for appropriate preoperative preparation and planning. Other preoperative studies would include a chest x-ray to check for any condition in the lung that would need to be treated prior to the surgery or any general anesthesia needs for surgery. The chest x-ray is also assessing for any possible evidence of the spread of cancer to the lungs.
Another common test is a CEA (carcinoembryonic antigen level) which is a blood test to check for a tumor marker that is made by most, but not all colorectal cancer tumors. The oncologist may occasionally request a PET (positron emission topography) in cases where there is increased concern about the possibility of distant spread of the tumor.
Prior to surgery patients will need to drink fluids that will clean the bowel of most of the stool (a mechanical bowel prep similar to what is done prior to colonoscopy). Surgeons will also often ask patients to take 1-2 antibiotic pills to decrease the bacterial count in the colon to minimize the risk of infection. Intravenous antibiotics will be given before and after surgery in the hospital to minimize the risk of infection.
Other, preoperative tests include an EKG to check for any cardiac issues that may need to be addressed prior to general anesthesia. Blood tests are performed checking for the presence of active infection, anemia (low blood count), and kidney function as well as electrolyte levels (sodium or potassium) which might need to be corrected so as to have the person in the best possible shape to undergo general anesthesia and major abdominal surgery. Though most patients will not require a blood transfusion during or after colon surgery one can never be certain what issues may be faced unexpectedly in the operating room preparations are made to have blood available for colon surgery in the event they are needed.
Post Operative Care Instructions
The majority of patients are able to leave the hospital 3-4 days after colon surgery if it is performed laparoscopically. Though the incisions are small your surgeon will likely ask you not to lift anything heavier than a gallon of milk for 6 weeks to minimize the risk of developing a hernia later, particularly through the incision through which the colon was extracted.
You will also be requested not to drive unless you are able to slam your brakes without pain in your parked vehicle in your driveway. We would not want you to find out on a high-speed road when you suddenly need to brake that you were unable to brake effectively and thus have an accident and potentially injure yourself or another person. Most surgeons request their postop colon surgery patients not to eat foods high in fiber or roughage such as raw fruits, vegetables or turnip greens for at least a week or two after surgery to minimize the risk of blockage at the potentially temporarily narrowed area where the intestine was put back together. Unless your surgeon says otherwise you should be able to shower or bathe upon arriving home.
Activities likely to speed healing and the return of energy include daily walks, a good multivitamin daily such as a Centrum Silver equivalent, a high-protein diet (meat, cheese, eggs and other milk products). Since the ecology of the colon is significantly disrupted by the mechanical bowel prep and the antibiotics, restoration of healthy intestinal flora using live culture yogurt such as Activa or cultured buttermilk or probiotic tablets or capsules (Lactinex granules or acidophilus tablets, for example) can help restore normal bowel function in a few days.
The body’s normal response to injury whether it is surgery, a motor vehicle accident or any other major would is as follows: First there is a massive energy expenditure and release of hormones such as adrenalin in order to stabilize the body following the injury; for weeks to months after this most of the energy from the food that is consumed will be directed toward healing the surgery or other wound; only after substantial healing has occurred will the body replenish the energy necessary for normal strength and endurance. Thus, taking a nap when you feel tired even if this is 2-3 times a day will likely help your body regain normal strength and endurance much faster.
Most surgeons would like to see their patient within 1-2 weeks following release from the hospital. You may be asked to return sooner if there are staples or a drain which needs to be removed in the office.