Colorectal cancer, also known as colon cancer, develops in either the large intestine or the rectum. According to the Centers for Disease Control and Prevention (CDC), colorectal cancer is the second leading cause of cancer deaths in the United States.
Cancer occurs when healthy cells become altered, growing and dividing in a way that keeps the body from functioning normally. Most cases of colorectal cancer begin as small, benign clusters of cells (polyps) on the lining of the colon or rectum. Certain types of polyps, called adenomas, can become malignant.
Risk Factors for Colorectal Cancer
There are several risk factors for colorectal cancer, some of which are under the patient’s control. They include the following:
- Being age 50 years or older
- Lack of exercise
- Excessive alcohol consumption
- Eating red or processed meats
- Certain hereditary syndromes
- Family history of colorectal cancer
- Patient history of inflammatory bowel disease
- Patient history of adenomas
- Patient history of other cancer
- Type 2 diabetes
Symptoms of Colorectal Cancer
While patients with colorectal cancer are often asymptomatic, as the disease progresses, they may experience one or more of the following symptoms:
- A change in bowel habits or a change in consistency of the stool
- Rectal bleeding or blood in the stool
- Persistent abdominal discomfort, such as cramps, gas or pain
- A feeling that the bowel does not empty completely
- Weakness or fatigue
- Unexplained weight loss
- Nausea or vomiting
Diagnosis of Colorectal Cancer
After performing a thorough physical examination and taking a full patient and family history, the doctor may administer other diagnostic tests, which may include the following:
- Blood tests (including a CBC), and tests for liver enzymes and tumor markers
- Digital rectal examination
- Fecal occult blood test
- Barium enema
- CT scans
As part of a colonoscopy or sigmoidoscopy, a biopsy may be taken.
Treatment of Colorectal Cancer
Depending on the stage of progression of the colorectal cancer, treatment may include one or more of the following:
- Surgical removal of diseased and immediately adjacent tissue
- Radiation therapy
- Targeted or biological therapy
Prevention of Colorectal Cancer
There are many steps that may be taken to lower the risk of developing colorectal cancer. Individuals may decrease their chances of developing this disease by eating a healthy low-fat diet, high in fiber and antioxidants, drinking alcohol only in moderation, exercising regularly, maintaining a healthy weight and refraining from smoking. For individuals at high risk for developing colorectal cancer, medications and surgery may be recommended. Everyone at high risk or 50 years of age and older, and African-Americans 45 years of age and older, should undergo a regularly scheduled colonoscopy, both to screen for cancer and to remove suspicious colorectal polyps at the earliest stage possible.
A colonoscopy is a diagnostic procedure performed to examine the inner lining of the colon, or large intestine, and the rectum. The colonoscopy procedure is performed routinely in patients over the age of 50 as a means detecting colorectal cancer in its early stages. It is also employed diagnostically to help determine the cause of abnormal bowel activity, abdominal pain or rectal bleeding. During a colonoscopy, tissue samples may be collected for a biopsy, and polyps or other abnormal growths may be removed.
Reasons for A Colonoscopy
Colonoscopies are recommended for people who are at increased risk of developing colorectal cancer. This type of cancer is much more effectively treated when it is detected early. Individuals at increased risk of developing colon cancer include those who:
- Have a personal or family history of colorectal polyps
- Have a personal or family history of colorectal cancer
- Have a personal or family history of inflammatory bowel syndrome (IBS)
- Are obese or have a poor diet
- Smoke or consume alcoholic beverages to excess
- Have diabetes
- Do not exercise regularly
All individuals over the age of 50 should undergo regular colonscopies and the procedure may be recommended for younger patients at elevated risk, whether they are experiencing symptoms or not.
Preparing For A Colonoscopy
In order to prepare for a colonoscopy, the colon must be cleansed so that its inner surface will be visible. Prior to the colonoscopy, patients are given written instructions which may vary a bit from one physician to another. Typically, the patient is told to drink clear liquids for a day or two before the procedure, including water, tea, coffee, strained fruit juices, sports drinks and clear broths. Patients are also permitted to consume gelatin. One strict prohibition is any liquid or gelatin with a red or purple coloration.
The day before the procedure, patients are instructed to drink a quantity of a special laxative solution or to take a large number of laxative pills. It is important that the patient remain close to home during this day because the toilet must be available for frequent use.
Patients who take aspirin or other blood-thinning medication must advise their doctors before going through the colonoscopy procedure. Most other medications can be continued.
The Colonoscopy Procedure
A colonoscopy is generally performed as an outpatient procedure. The patient is positioned on the left side and a sedative is administered intravenously. Once the patient is sedated, a colonoscope, a thin flexible tube with a camera attached to it, is gently inserted into the rectum. The colonoscope is then carefully snaked into the lower portion of the large intestine and guided upward toward the lowest portion of the small intestine. This enables the gastroenterologist to clearly visualize the entire length of the colon. Vital signs are closely monitored throughout the procedure.
The doctor watches the procedure on a computer monitor in real time and is able to see any abnormalities clearly. If necessary, tiny instruments will be inserted through the colonoscope to enable the surgeon to remove any polyps or other abnormal growths for biopsy. The procedure usually takes between 30 and 60 minutes to perform.
Recovery from a Colonoscopy
After the colonoscopy procedure, the patient is kept for observation for up to 2 hours, until the sedative wears off. Reflexes and judgment may be impaired and driving is not permitted for 24 hours after the procedure. Some people may experience pressure, bloating, nausea or cramping in the abdomen after the procedure, but these side effects are temporary. The patient should expect to expel an unusually large amount of gas after the procedure. This is considered normal.
Risks of a Colonoscopy
A colonoscopy is a safe, effective procedure. Nonetheless, as with any medical procedure, there is a slight risk of complication. Risks of a colonoscopy include:
- Abdominal pain
- Excessive bleeding
- Perforation of the bowel wall
- Adverse reaction to sedative medication
Despite the unpleasantness of the preparation and the very slight chance of a mishap during the procedure, the colonoscopy is an invaluable diagnostic tool that has saved countless lives.