Colorectal Cancer Screening 

Colorectal cancer is a painful disease wherein the cells of the rectum divide abnormally to form tumors and polyps. The initial symptoms often go unnoticed, but after detecting abnormalities, doctors usually suggest undergoing colorectal cancer screening.

We shall discuss the screening procedure in detail in the upcoming content.

When to take up the test?

Usually, colorectal screening is advised to men and women above 45 years of age who have had a family history.

Screening tests must also be performed when you observe the following symptoms:

• Blood in stool
  

• Itching and pain in the rectum while passing stool
  

• Severe constipation
  

• Tenderness in the lower abdomen
  

• Abnormal stools
  

• Random weight loss

Points to note:

The colorectal screening test is a must for people with inflammatory bowel disease, and it is usually performed after one year on those who have undergone surgery for colorectal cancer.
Anal flexible sigmoidoscopy must also be performed in the age group of 10-12 years on those with family history of familial adenomatous polyposis. 

Objectives of Colorectal Cancer Screening

The main objective of the tests is to detect colorectal cancer early, even if symptoms are not evident. This screening ensures early diagnosis of cancer and a 100% recovery. The outcome is – “saving lives of many.” Other than cancer, they also check for polyps and other abnormalities in the rectum, which could be cured by treatment.

Types of Colorectal Cancer Screening Tests 

Colonoscopy

Colonoscopy is a longer version of sigmoidoscopy. It involves a complete analysis of the colon and the rectum with the help of a colonoscope inserted via the rectum. 

A camera is attached at the end of the colonoscope, which is connected to a computer outside where your doctor can view the condition of your colon and rectum. During this process, a sample can be collected for biopsy purposes, or polyps can be removed. The entire process will take around 30 minutes, and your doctor may give a mild sedative before the test.

Flexible sigmoidoscopy

The basic procedure is the same as the colonoscopy. The only difference is that the sigmoidoscope is only 60 cms long, inserted into the rectum to view your entire rectum and part of the colon. Your doctor will not take more than 15 to 20 minutes for this. In most cases, sedatives are not given to patients, but a preliminary digital rectal exam is performed for easing the insertion of the sigmoidoscope. Colorectal cancers and polyps get easily detected with this technique.

Virtual Colonoscopy or CT Colonography

As the name suggests, an imaging technique computerized tomography (CT) is used to procure a cross-sectional or 3-D view of the large intestine and the rectum. The colon is enlarged by inserting a catheter filled with air through the rectum, which is painless. The test gives a clear picture of the abdominal organs, and it can detect how far cancer has spread in only 10 minutes.

Other Tests that are also a part of the screening:

Fecal Occult Blood Test (FOBT): 

It is also termed as stool DNA test (sDNA) or fecal immunochemical test (FIT)- involves testing the stool for hidden blood.

Double-contrast Barium Enema: 

It involves the use of barium sulfate solution pumped inside the intestine to get X-ray of the colon and intestine

How to Prepare for the Screening Tests

Do not get tensed or apprehensive about the screening test. Your doctor will examine you and then decide which test you need to undergo.

Secondly, consult with your doctor about your health problems, whether you are taking any medicines or laxatives and if you are pregnant.

Your rectum and colon should be empty. A day before the exam you may be asked to cleanse your colon with special fluids.

You may be given sedatives before the screening is done.

Possible Risks of Colorectal Cancer Screening Tests

Colorectal screening is the only way to detect cancer in the colon and rectum. However, in some cases, it can fall out for the following reasons:

False Negative: 

The fecal occult blood test sometimes shows a false negative test wherein the patient has cancer, but the test shows negative.

False Positive: 

This is just the opposite of the false negative. The patient is diagnosed with false cancer when she/he doesn’t have it.

In such cases, further tests are suggested for more accuracy.

During the tests, especially during colonoscopy and sigmoidoscopy, the patient may undergo lower abdominal pain, anal pain, and feel the urge to pass bowel. Dizziness and nausea are some other side effects.

However, these side effects are not a significant concern. In most cases, the tests are accurate and are the best diagnostic measures to start early treatment for colorectal cancer.