Colon cancer occurs in the large intestine(colon). The final part of the digestive tract is the colon. Colorectal cancer is the third most common cancer worldwide and typically affects men.
Until recently, colorectal cancer was thought to affect mostly people above 50. However, we know now that the cancer incidences are dropping in those above 50 but rising in the younger population.
As the cancer is often detected in the younger generation only after it has reached an advanced stage, knowledge about colorectal cancer symptoms and risk factors can make all the difference.
Colorectal cancer is silent in most cases, with cancer lurking anywhere in the 5- to an 8-feet-long passage from the colon to the rectum.
It doesn’t present any tell-tale symptoms in the initial stages. This is what makes screening essential.
Symptoms of colorectal cancer include:
1. Change In Bowel Habits
You may notice a change in your bowel habits, which may last more than a few weeks.
You may feel that your bowel has not been emptied. You may try to pass stool several times a day, but that is unlikely to rid you of the sensation.
2. Change In Bowel Movement
You may pass watery stool like in diarrhea. Or you may have difficulty passing stool like in constipation.
Often, episodes of diarrhea and constipation may alternate.
3. Narrow Stool
The stool might itself become narrow because of blocks in the colon and the rectal passage.
4. Blood And Mucus In Stool
If you don’t have piles or irritable bowel disorders, persistent blood in your stool or toilet bowl after a bowel movement requires a checkup.
Bright red blood may indicate cancer in the rectum or the last part of the colon, while dark or black stool indicates cancer higher up in the colon. There might be mucus too.
Some amount of mucus in your stool is not uncommon. But a persistently large amount of mucus in the stool, along with blood or change in bowel habits, indicates an infection or inflammation.
Your body produces a lot of mucus to heal itself.
5. Abdominal Pain, Bloating, And Nausea
You may experience bowel obstruction, which causes pain, discomfort, bloating, nausea, and vomiting after eating.
The symptoms may be present at every meal over a few weeks. This, in turn, reduces appetite and food intake, leading to weakness, fatigue, and weight loss.
Colorectal Cancer Symptoms Vs Piles, IBS, and IBD Symptoms
Colorectal cancer might be all the more difficult to detect because it shares similar symptoms with these conditions.
This is what makes screening for colorectal cancer so crucial after 50 and in some cases even earlier.
Piles or hemorrhoids also cause bleeding during a bowel movement. But the bleeding is often erratic. With colorectal cancer, however, the bleeding can persist over a few weeks or occur together with pain.
Irritable bowel syndrome (IBS) can cause diarrhea, constipation, and abdominal cramping. But if these are accompanied by bleeding, whether or not you have piles, you should get medical help.
Irritable bowel disorders, like ulcerative colitis and Crohn’s disease, have symptoms like abdominal pain, diarrhea, and bleeding.
Patients often complain that they haven’t been able to empty the bowel and feel the need to try again and again.
These patients also suffer from weight loss. IBD patients who have had colitis for 8 years or have 1/3 or more of their colon involved are at high risk and should screen for cancer. It is very difficult to differentiate between IBD and colorectal cancer based on symptoms.
Risk Factors Of Colorectal Cancer
About 75% of all colorectal cancers are caused by sudden gene mutations and environmental or lifestyle risk factors.
1. Too Little Vegetables And Fruits
Lack of fiber in your diet often leads to toxic waste building up in the colon. These release reactive molecules called free radicals which then damage cells and trigger inflammation.
If you don’t eat enough vegetables, leafy greens, and fruits that have antioxidants like flavonoids and carotenoids to fight the free radicals, you are making yourself more vulnerable to cancer risk.
Lack of vitamin B9 or folate, vitamin D, and calcium has been held responsible for increased cancer risk. Folate enables new cell and tissue formation and keeps red blood cells active and healthy.
Magnesium-rich foods like spinach and pumpkin seeds help too. Having garlic daily is also considered effective in lowering cancer risk. Here are a few other anticancer foods you should include in your diet.
2. Too Much Red Or Processed Meat
Red meat adds to your risk of colorectal cancer, especially colon cancer. When heated at a high temperature, these animal fats and proteins break down into certain cancer-causing amines and hydrocarbons.
Moreover, red meat like pork, veal, beef, and lamb contain heme iron, which is associated with a higher risk of colorectal cancer. Grass-fed beef, however, has cancer-fighting compounds.
Processed meat like cold cuts is even more unsafe. This is one of the reasons this cancer is so common in affluent and developed countries.
3. Too Much Alcohol
The onset of cancer, especially in the last or the distal part of the colon, is earlier in people who drink than in the general population. Sadly, this is true even for light drinkers.
You have a 21% increased risk of colorectal cancer if you drink more than 2 drinks. Any more than 3.5 drinks a day, you are 52% more likely to get colorectal cancer. For every 10 g, you pour down your throat, your cancer risk leaps by 7%.
4. Smoking Tobacco
In the United States, of every 100 casualties of this disease, 12 have smoking to blame. A Norwegian study reports that women who smoke are 20% more likely to get colon cancer than their counterparts who have never smoked.
Sadly, even passive smokers can get colorectal cancer and earlier than others. In their case, the screening test should be done at 40.
Nicotine Spreads The Cancer
Tobacco contains carcinogenic substances like nicotine and its compounds, including NNK. These can induce cancer cell growth and make the cells travel across the body, affecting other areas. The risk decreases when you quit smoking. And the younger you quit, the better.
5. Physical Inactivity And Overweight
Physical inactivity and excess body weight together account for about 25 to 33% of colorectal cancer incidences, and overweight men have a higher risk of colon cancer than overweight women.
This can be changed. Moderate or intense exercising can reduce the risk of colon cancer by 13 to 41%.
Exercise increases the metabolic rate and oxygen intake and improves the stretching and contraction of the gut muscles. This keeps the gut healthy and efficient.
6. Age Above 50 Years
Both men and women are at a high risk of colorectal cancer once they cross 50. 90% of people with colorectal cancer are 50 or older, with many more people in the 60–79 age bracket than in the 40 or below the bracket.
50 used to be a risky age, but now the millennials are at high risk.
As you grow old, gene mutations due to physical, chemical, and biological risk factors start effecting changes in your body. Plus your cell repair mechanism becomes weaker with age.
As a result, there’s an increase in new colorectal tissue growths, both benign and malignant. But there’s a delay in the death of these cells. So cancer grows and spreads rapidly.
The numbers, however, are rapidly changing, with more young people affected by the disease. Now, those born in 1990 have 2 times the risk of colon cancer and 4 times the risk of rectal cancer than those born in 1950.
This is possible because of greater exposure to environmental or lifestyle risk factors. Children are not entirely immune either if there’s a family history of colorectal cancer, colon tumors, and Lynch syndrome.
Conclusion: Prevent colorectal cancer by changing your lifestyle and make screening tests once you turn 50.
Go for colonoscopy and other tests to detect occult or hidden blood in the stool. Sometimes, you can’t see any trace of blood with the naked eye.
The colonoscopy will find if there are polyps or abnormal tissue growths in your colon. These are the precursors to cancer. Further tests can determine whether these polyps are benign or malignant.