Diagnosis of bowel cancer is made by imaging tests, such as colonoscopy and rectosigmoidoscopy, and by examining your stool, mainly the occult blood test in your stool. These tests are usually indicated by the doctor when the person develops signs and symptoms of bowel cancer, such as blood in the stool, changes in bowel rhythm, and weight loss. Here’s how to recognize symptoms of bowel cancer.
These tests are usually necessary for people over the age of 50 who have a family history of illnesses or who have a risk factor, such as obesity, diabetes, and a low-fiber diet, for example. However, these tests may also be recommended even in the absence of symptoms, only as a screening test, as diagnosis in the early stages of the disease increases the chances of recovery.
- Because there are several tests investigating the presence of this type of cancer.
- Your doctor should ask the right person.
- Taking into account factors such as health status.
- Cancer risk.
- And test cost.
- The main tests carried out are:.
The stool occult blood test is most commonly used in the detection of bowel cancer because it is practical, economical and noninvasive, and only requires a sample of stool by the person, which should be sent to the lab for testing. .
This test is designed to identify the presence of blood in the stool that is not visible, can occur in the early stages of bowel cancer, and is therefore indicated that people over the age of 50 are tested each year.
If the occult blood test is positive, your doctor should indicate more tests to confirm the diagnosis, with colonoscopy being primarily indicated, as in addition to cancer, bleeding can also be caused by polyps, hemorrhoids, diverticulosis or anal cleft, for example.
Currently, this test is performed with a new technique, called an immunochemical test, which is more advantageous than the traditional method, because it detects smaller amounts of blood and does not suffer from food interference, such as beetroot.
Learn more about stool occult blood research
Colonoscopy is a very effective diagnostic test for identifying intestinal changes because it is able to visualize the entire large intestine and, if changes are observed, it is always possible during the test to remove suspicious lesions or take a biopsy sample. Colonoscopy, on the other hand, is a procedure that requires bowel preparation and sedation.
Colonoscopy is therefore indicated for people who have altered the results of the occult blood test, who are over 50 years old, or who have suggestive signs or symptoms of bowel cancer, such as constipation or unwarranted diarrhea, blood and mucus in the stool. . Learn more about the colonoscopy exam.
Virtual colonoscopy is an examination that creates three-dimensional images of your intestine using CT scans, allowing you to look at both the outer wall of your intestine and your insides.
This is an excellent test because it can detect lesions such as cancer or polyps without sedation, such as in colonoscopy. However, despite its benefits, virtual colonoscopy is expensive, requires preparation of the intestine and whenever changes are detected, it may be necessary to complete the research with a colonoscopy.
Opaque enema is an imaging test that also helps identify changes in the intestine that can occur during cancer. To do this, it is necessary to insert a contrast fluid through the anus and then perform an X-ray that, thanks to the contrast, is able to form images of colon and rectum.
Currently, this test is not used much to detect bowel cancer, as in addition to the complexity to be performed, it can cause some discomfort or pain. In addition, it does not allow laboratory biopsy sampling and is often replaced by CT and colonoscopy.
Understand how this exam works and how to prepare for it
To perform this exam, a rigid or flexible tube is used with a small video camera at the tip, which is inserted by the anus and is able to observe the rectum and the final part of the large intestine, allowing the detection and elimination of suspected injuries. This test is best suited for over 50s, every 3 or 5 years, as well as for searching for occult blood in the stool.
Although it’s also a test that can identify bowel cancer, your doctor usually doesn’t order it, as colonoscopy provides more information.
The fecal DNA test is a new test for bowel cancer, also targeting people over the age of 50 or according to medical opinion, because it is able to identify changes in the DNA of cells that indicate cancer or precancerous lesions, such as polyps.
Its benefits include not preparing or modifying the diet, just taking a stool sample and sending it to the lab. However, whenever suspicious changes are identified, confirmation is required by another test, such as a colonoscopy.