At RS Surgical, we know that awareness saves lives. Colorectal cancer is the third most commonly diagnosed cancer in the United States and one of the leading causes of cancer-related deaths. Yet, when caught early, it is also one of the most preventable and treatable forms of cancer. That’s why understanding the symptoms of colorectal cancer and knowing when to act is so important.
What Is Colorectal Cancer?
Colorectal cancer is a type of cancer that begins in the colon (large intestine) or the rectum, which together form the final part of the digestive tract. Most colorectal cancers begin as adenomatous polyps, which are small, noncancerous (benign) clumps of cells. Over time, some of these polyps may become cancerous.
Because colorectal cancer often starts without symptoms, routine screening is essential. But it’s equally important to know the warning signs—especially if you’re under 50, when routine screening is less common and diagnosis is often delayed.
Why Early Detection Matters
When detected early, colorectal cancer has a 5-year survival rate of over 90%. Unfortunately, many people either ignore early symptoms or mistake them for less serious conditions like hemorrhoids or irritable bowel syndrome (IBS). Recognizing the signs and seeking timely medical attention dramatically improves outcomes and reduces the need for aggressive treatment.
The Most Common Colorectal Cancer Symptoms
Let’s break down the most frequently reported signs and symptoms. These symptoms may not always indicate cancer, but they do warrant medical evaluation—especially if they persist or worsen over time.
1. Changes in Bowel Habits
A sudden, unexplained shift in your normal bowel pattern could be an early red flag.
- Persistent constipation or diarrhea
- Alternating between constipation and diarrhea
- Narrow or ribbon-like stools
- Incomplete evacuation (feeling like your bowels aren’t fully emptied)
While minor irregularities can be common, consistency in change is the key factor. If your bathroom habits are different for more than a couple of weeks, it’s time to get checked.
2. Blood in the Stool or Rectal Bleeding
Bleeding can be one of the first signs of colorectal cancer—but it’s also one of the most frequently ignored. Many people assume it’s due to hemorrhoids or straining. Look out for:
- Bright red blood on toilet paper or in the bowl
- Dark, tarry stools (indicating older blood from higher up in the colon)
- Blood mixed with mucus
Even if bleeding is minimal or infrequent, it’s important to mention it to your doctor.
3. Unexplained Weight Loss
A sudden drop in weight without changes in diet or exercise is concerning. This symptom may indicate that your body is working harder to fight off cancer or that a tumor is interfering with digestion and nutrient absorption.
4. Abdominal Pain, Bloating, or Cramps
While abdominal discomfort is often associated with diet, stress, or minor digestive issues, persistent or worsening pain should be evaluated. Cancer can cause:
- Cramping that comes and goes
- Gas pain that doesn’t resolve
- Bloating or a feeling of fullness even after small meals
The key distinction? These symptoms linger and aren’t resolved by rest, diet changes, or over-the-counter remedies.
5. Fatigue and Weakness
This symptom is subtle but important. As colorectal cancer grows, it may cause chronic internal blood loss, which can lead to anemia. Anemia deprives the body of oxygen, resulting in fatigue, pale skin, shortness of breath, and general weakness.
6. Iron-Deficiency Anemia
Low iron levels may be your body’s way of signaling a hidden bleed in the gastrointestinal tract. Many patients only learn about their anemia through routine blood work, and further investigation leads to the cancer diagnosis.
Symptoms by Location
Colorectal cancer can affect different parts of the digestive tract, and symptoms can vary depending on tumor location.
Right-Sided (Ascending Colon) Cancer:
- Subtle or “silent” symptoms
- Fatigue and iron-deficiency anemia
- Occasional dark stools
Because this section of the colon has a wider diameter, tumors can grow larger before causing noticeable issues.
Left-Sided (Descending Colon) or Rectal Cancer:
- More obvious bowel changes
- Blood in the stool
- Narrow stools
- Cramping and bloating
Tumors here are more likely to obstruct the bowel, causing more pronounced symptoms early on.
How Colorectal Cancer Symptoms Differ From Other Conditions
It’s easy to misattribute some colorectal cancer symptoms to common conditions. Here’s how to tell them apart:
| Condition | Similar Symptom | How It Differs |
| Hemorrhoids | Rectal bleeding | Hemorrhoids usually cause bright red blood with no change in stool consistency |
| IBS | Bowel habit changes | IBS doesn’t usually cause weight loss, rectal bleeding, or anemia |
| Ulcerative Colitis/Crohn’s | Diarrhea, cramps | Inflammatory bowel disease often begins in youth and includes immune system markers |
| Diverticulitis | Pain, fever | Usually presents with more acute symptoms and infection |
When to Call a Doctor
If you’re experiencing any of the following for more than 2 weeks, seek medical attention:
- Blood in stool
- Persistent abdominal pain
- Long-lasting changes in bowel habits
- Chronic fatigue or weakness
- Unexplained weight loss
Don’t let embarrassment delay your visit. Gastrointestinal and colorectal symptoms are common, and specialists are trained to help you navigate them with compassion and discretion.
What to Expect During Evaluation
If you visit RS Surgical or your primary care provider with concerns about colorectal cancer symptoms, here’s what may happen next:
1. Medical History and Physical Exam
Your doctor will ask about your symptoms, lifestyle, family history, and perform a basic exam. This may include a digital rectal exam (DRE).
2. Diagnostic Tests
To confirm or rule out cancer, your provider may order:
- Colonoscopy (direct visualization and biopsy)
- Stool tests (e.g., FIT or stool DNA tests)
- CT scans or MRI (to assess spread or tumor size)
- Blood tests (for anemia or tumor markers like CEA)
Treatment Pathways After Diagnosis
If colorectal cancer is diagnosed, treatment will depend on the stage and location of the cancer.
Stage I–II:
- Often treated with surgery to remove the tumor and nearby tissue.
- Some may not need chemotherapy.
Stage III:
- Requires surgery and chemotherapy.
- Lymph node involvement indicates greater risk of recurrence.
Stage IV:
- Treated with a combination of surgery, chemotherapy, targeted therapies, or immunotherapy.
- Treatment focuses on prolonging life and improving quality of life.
At RS Surgical, our multidisciplinary team ensures a personalized approach to every treatment plan.
Prevention: Don’t Wait for Symptoms
The best way to reduce your risk is through routine screening and healthy lifestyle choices.
Screening Guidelines:
- Begin screening at age 45 (earlier if you have risk factors).
- Continue through age 75 based on individual health status.
- Common screening methods include colonoscopy, flexible sigmoidoscopy, and stool-based tests.
Lifestyle Choices That Help:
- Eat a diet high in fiber, low in red and processed meat.
- Exercise regularly.
- Maintain a healthy weight.
- Limit alcohol and quit smoking.
Listen to Your Body
Colorectal cancer often starts quietly, but your body gives you signals—subtle, persistent changes in how you feel or how your digestive system works. Recognizing colorectal cancer symptoms early gives you a fighting chance to prevent progression or detect cancer in its earliest, most treatable stages.
At RS Surgical, we’re committed to educating, screening, and supporting patients through every step of their colorectal health journey.
Take the Next Step
If you’ve noticed changes in your digestion or bowel habits, don’t wait.
Call RS Surgical today to schedule a screening or consultation.
Visit our website to explore our colorectal services, learn about prevention, and meet our compassionate care team.
You don’t need to navigate this journey alone. Let us help you protect your health—starting today.