Colon cancer is a result of the presence of cancerous tumors in the colon or the rectum. It is the third most commonly occurring form of cancer in the world. It usually starts off with small, precancerous polyps which can turn cancerous over time if they are left unchecked. Hence, screening colonoscopies can help one detect these polyps in the benign stage. Full recovery from colon cancer is possible, especially if the infection hasn’t spread beyond the colon wall.
Change in Bowel Movement
This is the most common symptom of colon cancer and is experienced in almost all of the cases. Colon cancer can lead to recurrent bouts of diarrhea or constipation for no apparent reason. Given their non-specific nature, these symptoms are often ignored by people or are combatted using over the counter medication. Note that if the symptoms do not resolve fast, one should see a doctor immediately.
Abnormal Stool Quality
Colon cancer can lead to a change in stool quality as well. In some cases, it can lead to long, thin “pencil stool,” which is thinner than a usual stool, or abnormal stool color – sometimes appearing dark due to bleeding in the digestive passage. Such signs are hard to miss, especially if they persist for a long time.
Rectal Bleeding
Colon cancer may lead to bleeding in the lower part of the digestive passage, and in some cases, in the rectum. Rectal bleeding leads to blood being visible as a separate discharge in the stool. Rectal bleeding is more common in individuals who suffer more bouts of constipation than diarrhea during the disease’s progression. Bleeding in a region above the rectum can change the color of stool to anywhere from a red to a tar-like black.
Abdominal Discomfort
People suffering from colon cancer can often experience abdominal pain of varying magnitude and frequency – even daily in some cases. It can cause feelings of fullness in the stomach and bloating, even if one has not eaten, and can lead to pelvic pain, stomach cramps, and even gas and belching. These symptoms can also point to several other conditions, such as GERD or IBS, and thus often tend to be misdiagnosed.
Anemia
Older people with colon cancer, especially those over the age of 50, tend to develop iron-deficiency, leading to anemia. Anaemia carries with it a range of symptoms, including weakness and general malaise. In very severe, but rare, cases, cardiac problems such as palpitations and angina may also be present.
Shortness of Breath
Some individuals suffering from colon cancer report frequent shortness of breath. It is mostly seen in older patients who develop anemia. Shortness of breath is an indicator of increasing pressure on the cardiovascular system, which in itself is a serious health hazard. Such a symptom calls for prompt medical attention.
Loss of Appetite
Appetite loss is also a common symptom of colon cancer. Some researchers believe that this is due to abdominal discomfort, which puts people off food. In cases where there aren’t many such accompanying symptoms, the reason for the loss of appetite is difficult to identify.
Decrease in Weight
Weight loss associated with colon cancer can be attributed to various factors, including appetite loss and increased energy expenditure. Increased energy is needed by cancer cells, which divide more rapidly and require more calories than normal cells due to their rapid growth rate. The body’s immune system also expends additional energy fighting the tumor.
Unexplained Fatigue
Colon cancer will kick the immune system into overdrive, thus leading to increasing energy expenditure and leaving one fatigued. Cancer cells also contribute to this fatigue thanks to their increased energy requirements. People with colon cancer who do not eat enough to offset this energy loss are likely to feel weak, lethargic, and sleepy for no apparent reason.
Nausea and Vomiting
In some cases of colon cancer, abdominal discomfort is accompanied by the urge to vomit. This urge may or may not provoke a physical response as well.