Screenings Matter: Understanding the Signs and Symptoms of Colorectal Cancer

March is Colorectal Cancer Awareness Month. As the fourth most common cancer in the U.S. and with more than 100,000 new cases each year, raising awareness for this disease is crucial – particularly since colorectal cancer is preventable and treatable when caught early. Let’s look at the common signs and symptoms. 

Signs and Symptoms of Colorectal Cancer 

Persistent changes in bowel habits.  

Changes in bowel habits, such as diarrhea or constipation, can be some of the earliest signs of colorectal cancer. The disruption to normal bowel movements is due to the tumor growing into the deeper layers of the intestinal tissues. Bowel obstruction can lead to constipation, while an overflow of intestinal fluid may cause diarrhea. 

Change in consistency of stool 

As the tumor grows, the intestinal passage narrows, resulting in narrow “pencil” stools. 

Blood in the stool 

Rectal bleeding may lead to blood in the stool, which may be bright red. This happens when polyps bleed into the digestive tract.    


Tumors can stimulate the formation of new blood vessels. The network of blood vessels is fragile, and vessels bursting can lead to the loss of blood causing anemia. 

Fatigue and weakness 

Fatigue and weakness can be related to iron deficiency or anemia caused by losing red blood cells. 

Abdominal pain 

Bowel movement changes and localized inflammation may cause abdominal pain. This discomfort often becomes persistent and feels like cramps or gas. 

Bloating and nausea 

Bloating is considered a late symptom of colorectal cancer, occurring due to an obstructing tumor and cancer spreading to nearby lymph nodes. Bloating and nausea commonly occur together, along with vomiting. 

Unexplained weight loss 

Cancer cells disrupt normal body function, changing how the body converts food into energy. As the tumor grows larger, it can create a blockage that affects regular bowel habits, resulting in bloating, nausea, and persistent abdominal pain. All of these things can cause patients to lose their appetite and experience rapid weight loss 

Early Detection and Screening 

It’s important to recognize that the symptoms of colorectal cancer do not usually present until the tumor has already grown. Therefore, catching precancerous polyps before they have had the chance to develop is crucial to colorectal cancer prevention. 

The majority of colorectal cancers can be prevented through regular screening It’s then that these precancerous polyps can get removed before they develop into cancer. Colorectal cancer detected in its early stages is highly treatable and curable. 

Screenings are recommended beginning at age 45. However, you may need to get screened earlier if you or a direct relative have had colorectal polyps or colorectal cancer. Having an inflammatory bowel disease also increases your risk. 

At Tampa Bay Radiation Oncology, more than a thousand men and women diagnosed with cancer each year turn to our trusted team of cancer specialists. We encourage you to call us, ask us a question, or consult with us to get a second opinion so you, too, can experience the difference.