10 Bowel (Colorectal) Cancer Warning Signs You Shouldn’t Ignore

Excluding skin cancers, colorectal cancer is the third most common cancer diagnosed in both men and women in the United States. If you're experiencing any of the symptoms described in this article, it's highly advisable to consult your doctor. While it could very well be nothing serious, getting it checked out offers peace of mind.

Before delving into the signs and symptoms, it's crucial to understand the factors that can increase your risk of developing this disease.

Risk Factors for Bowel (Colorectal) Cancer

Several factors can increase your likelihood of developing bowel cancer:

• Family History: There's strong evidence that bowel cancer can be hereditary. According to the NHS, approximately 20% of individuals who develop bowel cancer have a close relative (mother, father, brother, or sister) or a second-degree relative (grandparent, uncle, or aunt) who also had the disease.
• Diet: A substantial body of evidence suggests that a diet high in red and processed meat can increase the chances of developing bowel cancer. To reduce your risk, it's wise to maintain a healthy diet, low in saturated fat and high in fiber.
• Smoking: Smokers have an increased risk of developing bowel cancer, in addition to other types of cancer and heart disease.
• Alcohol: A major study, known as the EPIC study, linked alcohol consumption to bowel cancer risk. Worryingly, the study indicated that even small amounts of alcohol could increase your risk. The EPIC study showed that for every two units of alcohol a person drinks per day, their risk of bowel cancer increases by 8%.
• Obesity: Morbidly obese men and women face an increased risk of developing bowel cancer compared to those with a healthy weight.
• Inactivity: People who do not exercise regularly are more prone to developing bowel cancer than those who are physically active.
• Digestive Disorders: Individuals with Crohn's disease and ulcerative colitis have a higher likelihood of developing bowel cancer.
• Genetic Conditions: Certain inherited conditions can directly cause bowel cancer, such as familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC), also known as Lynch syndrome, among others.
• Racial and Ethnic Background: African Americans have a higher likelihood of developing bowel cancer than any other racial group in the United States. Jews of Eastern European descent (Ashkenazi Jews) also face an elevated risk of the disease.
• Type 2 Diabetes: Individuals with type 2 diabetes have an increased risk of developing bowel cancer. Both conditions share some common risk factors, such as excess weight.
• Night Shift Work: One study's results suggested that people who perform night shift work for at least three nights a month for a minimum of 15 years may have a higher risk of developing bowel cancer. However, more research is needed to confirm this link definitively.
• Previous Cancer Treatment: Some studies propose that men who survive testicular and prostate cancer may have an increased risk of developing bowel cancer, possibly due to the side effects of their cancer treatment.

Key Signs and Symptoms of Bowel (Colorectal) Cancer

While some of the symptoms below (like constipation or diarrhea) are commonly experienced by many people, they become concerning when they are persistent or accompanied by more specific signs of bowel cancer, such as bloody stools or rectal bleeding.

1. Blood in Stools: If you notice blood on or mixed with your stools, this could be a sign of bowel cancer. The blood may appear dark or bright red and can be mixed with mucus. Your doctor will likely send a stool sample for laboratory analysis (a fecal occult blood test).
2. Changes in Stool Consistency or Shape: If your stools become very dark or even black and sticky (often described as "tarry"), this could indicate bleeding related to bowel cancer. You might experience normal bowel movements in between these abnormal stools. Additionally, pay attention if your stools become very narrow or ribbon-like, perhaps only as wide in diameter as a pen.
3. Rectal Bleeding: According to an article published in BMC Medicine in July 2009, "Bleeding from the rectum occurs in more than half of people with colon cancer." The blood is usually bright red and may be visible in the toilet bowl water or on toilet paper. This bleeding might occur after a painful bowel movement.
4. Trouble Passing Stool (Changes in Bowel Habits): You may experience a persistent feeling of not completely emptying your bowels after a stool, or a frequent, urgent need to have a bowel movement even when there's no stool to pass.
5. Anemia: Blood loss from bowel cancer can lead to anemia, a shortage of red blood cells. Symptoms of anemia include feeling tired most of the time, weakness, shortness of breath, and pale skin. Anemia can be detected by an MCHC (Mean Corpuscular Hemoglobin Concentration) blood test, which checks the concentration of hemoglobin in your red blood cells.
6. Abdominal Pain: While some abdominal discomfort is normal, persistent gas, cramping, or bloating that doesn't resolve should be a cause for concern. It's best to discuss such symptoms with your doctor.
7. Unexplained Weight Loss: Bowel cancer can cause weight loss even if your eating habits remain normal. Alternatively, you might experience a complete loss of appetite. The BMC Medicine article from July 2009 noted that more than a third of people with bowel cancer experience unexplained weight loss.
8. Persistent Constipation: Constipation that lasts for more than a few days and doesn't resolve could be associated with colon cancer. Chronic or ongoing constipation may even increase your risk of developing colon cancer.
9. Persistent Diarrhea: Chronic diarrhea is also a symptom of bowel cancer. According to the BMC Medicine article, more than 1 in 5 people with colon cancer will experience diarrhea.
10. Persistent Nausea and Vomiting: If you're experiencing ongoing nausea and vomiting without any clear reason, this may be a symptom of colon cancer. These symptoms can occur with or without other abdominal discomforts.

If you suspect something is wrong, please consult your doctor. Early detection is a crucial factor for the best possible outcome in treating bowel cancer.