Signs and symptoms
The 3 main symptoms of bowel cancer are blood in the stools (faeces), changes in bowel habit – such as more frequent, looser stools – and abdominal (tummy) pain. However, these symptoms are very common and most people with them do not have bowel cancer.
Sometimes colon cancer can cause fatigue due to internal blood loss from the disease. In many cases, the symptoms of colon cancer are connected. Other colon cancer symptoms, such as unintentional weight loss and a change in bowel habits, can increase the feeling of weakness.
Many cases of colon cancer have no symptoms. If there are symptoms, the following may indicate colon cancer: Abdominal pain and tenderness in the lower abdomen. Blood in the stool.
Persistent abdominal discomfort
You may also feel full, bloated, or like your bowel is not completely empty. Nausea and vomiting can also be symptoms.
Alternating constipation and diarrhea: A more telling sign of colon cancer. Blood in stool: Also known as hematochezia , which can be bright red if the tumor is near the rectum or dark red or maroon if higher up in the colon.
Colon cancer is typically slow-growing, starting as a benign polyp that eventually becomes malignant. This process may occur over many years without producing any symptoms. Once colon cancer has developed, it may still be years before it is detected.
In most cases, colon and rectal cancers grow slowly over many years.
Though not as common, a person may experience excessive smelly gas due to the presence of cancer of the colon. Cancerous polyps or tumors can form blockages that cause gas to build up in the intestine. One early warning sign is when changes in diet or medication do not stop foul-smelling gas from occurring.
Stool tests.
Currently, three types of stool tests are approved by the US Food and Drug Administration (FDA) to screen for colorectal cancer: guaiac FOBT (gFOBT); the fecal immunochemical (or immunohistochemical) test (FIT, also known as iFOBT); and multitargeted stool DNA testing (also known as FIT-DNA).
During treatment for colon cancer, a new host of reasons for fatigue appear. Radiation and chemotherapy are both extremely hard on the human body, and can cause complete fatigue and the need for extra sleep for a majority of each 24-hour period.
Colon cancer symptoms may include changes in bowel movements or stool shape. However, there is no specific colon cancer stool shape. Regular screenings are the best way to identify signs of colon cancer early. Colon cancer begins in the colon but can spread to other body parts.
Lenhart said, colon cancer patients describe symptoms including gastrointestinal bleeding, bowel obstruction, nausea, weight loss and constipation or diarrhea. “Polyps and early cancer can often be asymptomatic,” she said. “The point is to be able to detect things early. Not all patients are going to have GI symptoms.”
Cancer and its treatment may cause problems that lead to patients having leg and other types of muscle cramps. Leg cramps or spasms are painful tightenings of the muscles in the leg, ankle, or foot.
Abdominal symptoms such as pain, bloating or rectal bleeding are often signs of an abnormal process in the left side of your colon. “Right-sided colon cancers tend to be asymptomatic or cause these symptoms only when they are at an advanced stage and fairly large.
Other symptoms may also appear at this later stage. Back pain can sometimes occur with colorectal cancer. It is typically radicular pain, or nerve pain. This type of pain results from pressure on the underlying nerve root, for example, when a tumor or swelling presses upon the spine.
Pantel says, “you should get checked out if you have rectal bleeding, if you have any change in your bowel habits, any change in appetite (like feeling “full” early), weight loss, or abdominal pain that is not explained.” Your symptoms may be different than those of someone you know who had colorectal cancer.
Usually if a suspected colorectal cancer is found by any screening or diagnostic test, it is biopsied during a colonoscopy. In a biopsy, the doctor removes a small piece of tissue with a special instrument passed through the scope. Less often, part of the colon may need to be surgically removed to make the diagnosis.