Understanding Colorectal Cancer: Symptoms, Causes, Risk Factors, and Treatment Options

Colorectal cancer develops in the colon and/or rectum, both of which play vital roles in processing and eliminating waste from the body. The silver lining is that colorectal cancer often develops slowly, which makes it largely preventable and highly manageable when detected at an early stage. Although it is a commonly diagnosed cancer, most people are still unaware about how it develops and the importance of early screening.

What is Colorectal Cancer?

Colorectal cancer is a type of cancer that begins in the colon or the rectum, which together form the large intestine. The colon absorbs water and minerals from digested food, while the rectum stores waste before it is eliminated from the body. Cancer can develop in either of these areas and is often referred to collectively as colorectal cancer.

In most cases, colorectal cancer develops gradually. It usually starts as a benign growth called a polyp on the inner lining of the colon or rectum. Over time, some polyps can undergo abnormal cellular changes and turn cancerous if they are not detected and removed early. This slow progression is one of the reasons colorectal cancer is considered highly preventable and treatable when identified at an early stage.

Although colon cancer and rectal cancer share many similarities, their location within the large intestine can influence how they are evaluated and treated.

Causes and Risk Factors for Colorectal Cancer

Colorectal cancer develops due to a combination of genetic, lifestyle, and medical factors. While some of these factors are beyond an individual’s control, others are related to long-term habits and health conditions that can influence risk over time.

The following factors are known to increase the likelihood of developing colorectal cancer:

• Increasing Age: The risk of colorectal cancer rises with age, particularly after the age of 45. Age-related changes in cells and prolonged exposure to risk factors contribute to this increased susceptibility.
• Family History and Inherited Conditions: Individuals with a close family member diagnosed with colorectal cancer or certain inherited genetic conditions have a higher risk. These genetic factors can lead to abnormal cell growth in the colon or rectum.
• Diet High in Red or Processed Meat: Regular consumption of red meat and processed foods has been linked to a higher risk of colorectal cancer. Diets low in dietary fibre and high in fats may also contribute to unhealthy changes in the colon.
• Sedentary Lifestyle and Obesity: Lack of physical activity and excess body weight are associated with an increased risk. Regular exercise helps improve bowel function and reduce inflammation.
• Smoking and Alcohol Use: Tobacco use and heavy alcohol consumption have been shown to increase the risk of several cancers, including colorectal cancer, by damaging cells and weakening the body’s protective mechanisms.
• Inflammatory Bowel Disease (IBD): Long-standing conditions such as ulcerative colitis or Crohn’s disease increase the risk of colorectal cancer due to chronic inflammation of the intestinal lining.
• Type 2 Diabetes: People with type 2 diabetes may have a higher risk of colorectal cancer, possibly due to shared metabolic and inflammatory factors.

Understanding these causes and risk factors can help individuals identify their level of risk and take appropriate steps toward screening, lifestyle modification, and timely medical consultation.

Symptoms and Warning Signs of Colorectal Cancer

The symptoms of colorectal cancer can vary from person to person and may develop gradually. In many cases, early symptoms are mild and easily overlooked or mistaken for common digestive problems. Being aware of both subtle changes and more concerning warning signs can help prompt timely medical evaluation.

The following symptoms and signs are commonly associated with colorectal cancer:

• Changes in Bowel Habits: This may include persistent diarrhoea, constipation, or a change in the frequency or consistency of stools that lasts for more than a few days.
• Blood in the Stool or Rectal Bleeding: Blood may appear bright red or cause stools to become dark or black. Rectal bleeding should never be ignored, even if it is painless.
• Abdominal Discomfort or Cramping: Ongoing abdominal pain, bloating, or cramps that do not settle may be an early indication of bowel-related disease.
• Feeling of Incomplete Bowel Evacuation: A persistent sensation that the bowel has not emptied fully after passing stools can be a warning sign, especially when it occurs repeatedly.
• Unexplained Weight Loss: Losing weight without changes in diet or physical activity can occur as the body’s metabolism is affected by cancer.
• Persistent Fatigue or Weakness: Long-standing tiredness may be linked to anaemia caused by chronic blood loss from the bowel.
• Iron Deficiency Anaemia: Low iron levels, particularly when unexplained, can be an early indicator of slow blood loss from the colon or rectum.

Because colorectal cancer may not cause symptoms in its early stages, any persistent, unexplained, or worsening digestive changes should be discussed with a doctor rather than dismissed as routine gastrointestinal issues.

When Should You Consult a Specialist?

While many bowel-related symptoms can be caused by non-cancerous conditions, certain changes should not be ignored, especially when they persist or worsen over time. Consulting a specialist at the right time allows for appropriate evaluation and helps rule out serious underlying conditions such as colorectal cancer.

You should consider seeking specialist medical advice if you experience:

• Bowel symptoms, such as changes in stool frequency or consistency, that last for more than two weeks
• Recurrent or unexplained rectal bleeding, even if it appears mild or painless
• Sudden or persistent changes in bowel habits without an obvious cause
• A family history of colorectal cancer along with new digestive symptoms
• Unexplained iron deficiency anaemia, ongoing fatigue, or unintended weight loss

Early consultation does not necessarily mean a diagnosis of cancer, but it ensures timely investigations and appropriate guidance, which can be crucial for early detection and effective management.

How is Colorectal Cancer Diagnosed?

Diagnosing colorectal cancer involves a combination of clinical evaluation, screening tests, and imaging studies to accurately identify the presence, location, and extent of the disease. The choice of tests depends on symptoms, risk factors, and initial findings.

Common methods used to diagnose colorectal cancer include:

• Clinical Evaluation and Medical History: A doctor will assess symptoms, family history, lifestyle factors, and perform a physical examination to determine the need for further tests.
• Stool-Based Tests: These tests check for hidden (occult) blood or other abnormalities in the stool that may suggest bleeding from the colon or rectum. While useful for screening, they are not conclusive on their own.
• Colonoscopy with Biopsy: Colonoscopy is the most definitive test for colorectal cancer. It allows direct visual examination of the colon and rectum and enables removal of polyps or biopsy of suspicious areas for confirmation.
• Imaging Tests: Scans such as CT, MRI, or PET-CT help determine the extent of disease, assess lymph node involvement, and identify any spread to other organs.

Accurate diagnosis is essential for staging the disease and planning the most appropriate treatment approach.

Stages and Treatment of Colorectal Cancer

The stage of colorectal cancer describes how far the disease has progressed at the time of diagnosis. Staging helps doctors understand whether the cancer is limited to the bowel or has spread to nearby lymph nodes or distant organs, and it plays a key role in deciding the most appropriate treatment approach.

Treatment is planned based on the stage of the disease, overall health, and tumour location, with the aim of achieving the best possible outcome while maintaining quality of life.

• Early-Stage Colorectal Cancer: When cancer is confined to the colon or rectum, surgery is usually the primary treatment. Surgical removal of the tumour may be sufficient in many early cases, especially when the disease is detected before it spreads.

Locally Advanced Colorectal Cancer: If the cancer has spread to nearby lymph nodes or surrounding tissues, treatment often involves a combination of surgery and chemotherapy. In rectal cancer, radiation therapy may be used before or after surgery to reduce the risk of recurrence and improve local control.

• Metastatic Colorectal Cancer (Stage IV): In advanced stages where cancer has spread to distant organs, treatment focuses on controlling disease progression, reducing symptoms, and improving quality of life. Chemotherapy, targeted therapy, and immunotherapy may be used depending on tumour characteristics, along with palliative care to manage symptoms and support comfort.

Advances in cancer treatment have made it possible to tailor therapy according to disease stage and individual patient needs, allowing for more personalised and effective colorectal cancer care.

How Can Colorectal Cancer Be Prevented?

While colorectal cancer cannot always be prevented, especially in individuals with genetic risk factors, several measures can help reduce risk and support earlier detection. A preventive approach focuses on regular screening and long-term lifestyle habits that promote bowel health. Some of the effective preventive measures include:

• Regular Colorectal Cancer Screening: Screening helps detect precancerous polyps or early-stage cancer before symptoms appear. Timely screening is particularly important for individuals above a certain age and those with a family history or other risk factors.
• Healthy Diet and Lifestyle Choices: A balanced diet that includes fruits, vegetables, whole grains, and adequate dietary fibre supports healthy bowel function. Limiting red and processed meat and reducing highly processed foods may help lower risk.
• Regular Physical Activity: Staying physically active helps maintain a healthy weight, improves digestion, and reduces inflammation, all of which contribute to lower colorectal cancer risk.
• Avoiding Smoking and Excess Alcohol: Tobacco use and heavy alcohol consumption are linked to an increased risk of colorectal and other cancers. Avoiding these habits supports overall digestive and metabolic health.
• Managing Long-Term Medical Conditions: Proper management of conditions such as inflammatory bowel disease or type 2 diabetes, along with regular medical follow-up, can help reduce cancer-related risks.
• Use of aspirin in selected cases of lynch syndrome.

Adopting preventive measures and participating in recommended screening programmes play an important role in reducing the burden of colorectal cancer and improving long-term outcomes.

Why Choose RGCIRC for Colorectal Cancer Care

Colorectal cancer care requires accurate diagnosis, coordinated treatment planning, and long-term follow-up, especially as the disease can vary widely in its symptoms and stage at diagnosis. RGCIRC (Rajiv Gandhi Cancer Institute and Research Centre) provides a comprehensive, structured approach to colorectal cancer management, supported by specialised expertise and advanced infrastructure. Here’s why people trust RGCIRC for Colorectal cancer care:

• Exclusive Focus on Cancer Care: As a dedicated oncology centre, RGCIRC brings focused experience in diagnosing and treating gastrointestinal cancers, including colorectal cancer, ensuring care that is aligned with current evidence and best practices.
• Multidisciplinary Tumour Board Approach: Each case is reviewed by a team of surgical oncologists, medical oncologists, radiation oncologists, radiologists, pathologists, and supportive care specialists. This collaborative approach ensures that treatment decisions are personalised and stage-appropriate.
• Advanced Diagnostics and Precise Staging: RGCIRC is equipped with modern imaging, endoscopy, and pathology services that support accurate diagnosis and staging, which are essential for effective treatment planning.
• Comprehensive Treatment Under One Roof: From colorectal cancer surgery and systemic therapies to radiation therapy and supportive care, patients receive coordinated care across all stages of the disease, reducing delays and improving continuity.
• Ethical and Research-Driven Care with Long-Term Support: Treatment recommendations are guided by clinical evidence and transparency, with emphasis on patient wellbeing, symptom management, rehabilitation, and structured follow-up.

This integrated approach allows RGCIRC to deliver colorectal cancer care that is precise, patient-focused, and tailored to individual needs.

Taking the Next Step Towards Expert Colorectal Cancer Care

Colorectal cancer is highly manageable when detected early, and timely medical evaluation can significantly influence treatment outcomes. Awareness of symptoms, understanding risk factors, and participation in regular screening are key steps in protecting long-term bowel health. In addition, access to specialised cancer care ensures that concerns are assessed thoroughly and treatment decisions are made with clarity and confidence. To consult a cancer specialist at RGCIRC, simply call +91-11-47022222, +91 11 27051037

Frequently Asked Questions

Q: What are the first warning signs of colorectal cancer?

Early warning signs may include persistent changes in bowel habits, blood in the stool, abdominal discomfort, unexplained fatigue, or unintended weight loss. Symptoms that continue or worsen over time should be evaluated.

Q: Can colorectal cancer be detected early?

Yes. Colorectal cancer can often be detected early through screening tests, even before symptoms appear. Early detection allows timely treatment and can significantly improve outcomes.

Q: When should I see a specialist for bowel symptoms?

You should consult a specialist if bowel changes last more than two weeks, if there is recurrent rectal bleeding, unexplained anaemia, weight loss, or if you have a family history of colorectal cancer with new symptoms.

Q: Is blood in the stool always a sign of cancer?

No. Blood in the stool can be caused by conditions such as piles, fissures, or infections. However, it should never be ignored, and medical evaluation is necessary to rule out serious causes, including colorectal cancer.

Q: What age should colorectal cancer screening start?

Screening is generally recommended from the age of 45 onwards. People with a family history, inflammatory bowel disease, or other risk factors may need to begin screening earlier, as advised by a doctor.

Q: Can colorectal cancer occur without symptoms?

Yes. Colorectal cancer may not cause noticeable symptoms in its early stages, which is why regular screening is important, especially for individuals at higher risk.

Q: How fast does colorectal cancer grow?

Colorectal cancer usually grows slowly and may take several years to develop from a benign polyp into cancer. This slow progression provides an opportunity for early detection through screening.

Q: What tests confirm colorectal cancer?

Colonoscopy with biopsy is the definitive test for confirming colorectal cancer. Imaging tests such as CT or MRI scans are used to assess the extent of the disease.

Q: Is colorectal cancer curable?

Colorectal cancer is often treatable, particularly when detected at an early stage. Treatment outcomes depend on the stage of the disease, tumour characteristics, and overall health.

Q: Can piles be mistaken for colorectal cancer?

Yes. Symptoms such as rectal bleeding or discomfort caused by piles can resemble those of colorectal cancer. This is why proper medical evaluation is important rather than self-diagnosis.

Q: How long should bowel changes last before concern?

Any change in bowel habits that lasts longer than two weeks, especially if accompanied by bleeding, pain, or weight loss, should be assessed by a doctor.

Q: Does colorectal cancer cause weight loss?

Unexplained weight loss can occur in colorectal cancer, particularly in more advanced stages, due to changes in metabolism and reduced nutrient absorption.

Q: What foods increase colorectal cancer risk?

Diets high in red meat, processed meat, and low in dietary fibre are associated with an increased risk. A balanced diet with fruits, vegetables, and whole grains supports bowel health.