Rectal Cancer – Symptoms and Causes

Overview

Rectal cancer develops when cells in the rectum begin to grow abnormally. The rectum forms the final inches of the large intestine, connecting the end of the colon to the anus.

Doctors often discuss rectal and colon cancers together as colorectal cancer because they share many similarities.

Despite these similarities, treatment approaches differ significantly. The rectum’s confined location near other organs makes surgical intervention more challenging than colon cancer treatment.

Treatment typically includes:

• Surgery to remove cancerous tissue
• Radiation therapy
• Chemotherapy
• Targeted therapy
• Immunotherapy

These treatments may be used alone or in combination. Healthcare providers create personalized treatment plans based on the cancer’s stage, location, and other health factors.

The tight anatomical space surrounding the rectum requires specialized surgical techniques. This anatomical challenge explains why treatment protocols differ from those used for colon cancer, even though both are types of colorectal cancer.

Signs of Rectal Cancer

Rectal cancer often doesn’t show symptoms in its early stages. Most people notice problems only when the disease has advanced.

Common symptoms of rectal cancer include:

• Changes in bowel movements (diarrhea, constipation, or more frequent bathroom trips)
• Incomplete bowel emptying feeling
• Pain in the abdomen
• Blood in stool (either dark maroon or bright red)
• Narrower than normal stool
• Unexplained weight loss
• Feeling weak or tired without explanation

When to See a Healthcare Provider

If you notice any concerning symptoms, especially changes in your bowel habits or blood in your stool, make an appointment with your doctor right away. Early detection can make a significant difference in treatment options and outcomes.

These symptoms may develop gradually. Many people dismiss early warning signs as temporary digestive issues. Don’t ignore these changes in your body, especially if they persist for more than a few days.

Causes

Scientists don’t fully understand what triggers most rectal cancers. These cancers develop when cells in the rectum undergo DNA changes. In healthy cells, DNA provides instructions for normal growth, reproduction, and death. When DNA becomes altered, these instructions change dramatically.

Altered DNA tells cancer cells to multiply rapidly without dying when they should. This uncontrolled growth creates an excess of cells that may form tumors. These tumors can invade and damage surrounding healthy tissue.

Over time, cancer cells may break away from the original tumor. They can travel through the bloodstream or lymphatic system to other body areas. This spreading process is called metastasis.

DNA changes can happen for various reasons. Some people inherit altered genes that increase their cancer risk. Meanwhile, environmental factors and lifestyle choices might also contribute to DNA damage that leads to cancer.

The aging process naturally increases rectal cancer risk, with most cases diagnosed in people over 50.

Risk Factors

Several factors can increase your chance of developing rectal cancer. These risk factors are the same as those for colon cancer.

• Personal History: If you’ve previously had rectal cancer, colon cancer, or adenomatous polyps, your risk is higher than average.
• Race: Black individuals in the United States face a greater risk of developing colorectal cancer compared to other racial groups.
• Health Conditions: People with type 2 diabetes may have an elevated risk. Inflammatory bowel diseases like ulcerative colitis and Crohn’s disease also increase the likelihood of colorectal cancer.
• Lifestyle Factors:
  • Heavy alcohol consumption
  • Diets low in vegetables and high in red meat
  • Smoking
  • Physical inactivity
  • Obesity
• Family History: Having a parent, sibling, or child with colorectal cancer raises your risk level.
• Genetic Factors: Some inherited DNA changes can increase colorectal cancer risk, including:
  • Familial adenomatous polyposis (FAP)
  • Lynch syndrome
  • Other rare inherited syndromes
• Age: While colorectal cancer can occur at any age, most people diagnosed are over 50. However, rates in people under 50 have been rising for reasons not yet fully understood.
• Previous Cancer Treatment: Radiation therapy directed at the abdomen for previous cancers may increase the risk of developing colorectal cancer later.

This table summarizes the main risk factors:

Risk Factor Category	Examples
Medical History	Previous colorectal cancer, polyps, inflammatory bowel disease
Demographics	Black race, older age (50+)
Lifestyle	Heavy drinking, poor diet, smoking, lack of exercise
Genetic	Family history, inherited syndromes (FAP, Lynch)
Other	Previous abdominal radiation, obesity, diabetes

Complications

Rectal cancer can cause several serious issues. Blood may appear in the rectum as the cancer grows. In some cases, bleeding becomes severe enough to need immediate medical care.

The cancer can grow large enough to block the intestines. This blockage stops stool from moving through the digestive system. Doctors usually perform surgery to remove the cancer and clear the obstruction.

In some situations, rectal cancer can cause a tear in the intestinal wall. This dangerous condition, called perforation, typically requires surgical repair.

Ways to Reduce Your Risk

Talk to Your Doctor About Cancer Screenings

Regular screenings can find growths in your colon and rectum before they become cancer. These tests save lives by catching problems early. Most health experts suggest starting screenings at age 45.

You might need to start earlier if cancer runs in your family or you have other risk factors. Many screening options exist, from simple at-home tests to more detailed exams. Discuss which test works best for you with your doctor.

Limit Alcohol Consumption

If you drink alcohol, do so in small amounts. For women, this means no more than one drink per day. Men should have no more than two drinks daily. Some people choose not to drink at all, which may further reduce risk.

Eat More Plant Foods

Fill your plate with fruits and vegetables every day. These foods contain natural compounds that may help protect your body.

Try to get your vitamins from food rather than supplements. Large doses of vitamin pills might actually be harmful for some people.

Stay Physically Active

Try to exercise for at least 30 minutes on most days. This could be walking, swimming, biking or any activity you enjoy. If you haven’t exercised recently, check with your doctor first and start slowly. Even small increases in activity can help.

Keep a Healthy Weight

If your weight is in a healthy range now, work to maintain it. If you need to lose weight, talk to your doctor about safe approaches. Focus on eating fewer calories and gradually increasing your physical activity level.

Quit Tobacco

If you smoke, quitting is one of the best things you can do for your health. Many tools can help. These include nicotine replacement products, prescription medications, support groups, and counseling programs.

If you don’t smoke, don’t start. Avoiding tobacco in all forms helps reduce cancer risk.