The symptoms of colon cancer and rectal cancer are not always easy to recognize, which misses opportunities for early diagnosis. On the one hand, many people with cancer of the colon or rectum (known as colorectal cancer) do not experience any symptoms until the disease reaches a more advanced stage, when treatment is more difficult. This is why testing apparently unaffected people is of the utmost importance.
Early detection: a major asset
The decline in colorectal cancer deaths in recent decades is due in part to increased screening efforts that identify asymptomatic cancers. Screening tests can also identify abnormal growths called colorectal polyps, some of which may be precancerous. When doctors remove potentially dangerous polyps, they stop cancer before it starts. Another complication of diagnosing colon and rectal cancer is that even when symptoms are present, both people with cancer and doctors may blame other common conditions, such as hemorrhoids or irritable bowel syndrome.
Many younger people also think that colon and rectal cancer only affects older people, so they may not be aware of the symptoms. However, while the vast majority of colorectal cancers still occur in older people, the incidence in men and women under 50 is rising sharply.
7 signs and symptoms of colon and rectal cancer
Regardless of your age, the following symptoms should prompt you to see a doctor:
- A change in bowel movements such as diarrhoea, constipation or narrowing of the stool (stool) that lasts for more than a few days.
- A feeling of needing to defecate that is not relieved by defecation.
- Rectal bleeding with bright red blood
- The presence of blood in the stool, which can make it appear dark.
- Abdominal (abdominal) cramps or pain
- Weakness and fatigue
- Unintentional weight loss
Although people with colorectal cancer may not experience rectal bleeding or blood in the stool, for many these are the most identifiable symptoms of the disease.
These symptoms occur when the cancer spreads through the digestive tract. This can happen very slowly, over years, so the presence of blood in the stool may not even be noticeable. Over time, this continued blood loss can lead to a decrease in the number of red blood cells, a condition called anemia. Blood tests that diagnose anemia may be the first step in diagnosing colon or rectal cancer.
Discuss your symptoms with your doctor
Once you describe your symptoms to your doctor, they will likely give you physical information to determine the cause. Your doctor will likely ask about your medical history and ask if any family members have had colorectal cancer, especially your parents, siblings, or children. Most people who develop colorectal cancer have no family history of the disease, but 1 in 5 do.
Major risk factors for colorectal cancer
In rare cases, genetic mutations passed down through families, such as Lynch syndrome, can make a person extremely vulnerable to colon and rectal cancer. Your doctor will want to know if you have other medical conditions, especially those involving the colon and rectum, that may increase your risk of colorectal cancer. This may include a history of colorectal cancer or precancerous polyps, or an inflammatory bowel disease such as Crohn’s disease or ulcerative colitis. There is also a link between type 2 diabetes and colorectal cancer. Other risk factors include obesity or being overweight, low levels of physical activity, heavy alcohol consumption and smoking.
What tests to get to the bottom of it?
A physical examination and blood tests are part of the medical examination. Once your doctor knows your medical history, the next step may be a physical examination of your body, which includes gentle pressure on your abdomen to detect any lumps or enlarged organs. The doctor may also examine your rectum by inserting a lubricated, gloved finger into it to check for any abnormalities. The doctor may order blood tests to detect changes that indicate the presence of colorectal cancer.
It’s not just a test to see if you’re anemic, but also tests that measure liver enzymes and substances called tumor markers. If you have not experienced rectal bleeding or blood in your stool, your doctor may recommend a test to identify occult blood. These tests, which include a stool blood test and a fecal immunochemical test, involve collecting one or more stool samples at home, packaging them in a special container, and returning them to the doctor’s office or medical laboratory.
Your doctor may suggest a colonoscopy
You can also leave the office with a prescription for a diagnostic colonoscopy. During this procedure, a gastroenterologist examines the inside of the colon and rectum using a device inserted through the anus: a long, thin, flexible light tube with a small video camera attached to the end. If the exam reveals any suspicious growths, the gastroenterologist may take tissue for a biopsy to see if cancer cells are present. The night before a colonoscopy, people having the test should clean their colon and rectum. This procedure involves drinking a strong laxative solution. People who have a colonoscopy are usually sedated during the procedure.
Do you like our content?
Get our latest publications free and delivered straight to your inbox every day