Blood in Stools: Haemorrhoids or Cancer?

What Are the Many Possible Causes of Blood in Stool?

Blood in the stool can arise from various underlying conditions, ranging from mild to more serious conditions. Identifying the cause is essential for proper treatment. While the bleeding may appear in the stool, it can originate from different parts of the gastrointestinal (GI) tract — which is why a thorough assessment is key.

Common causes of blood in stool include:

• Anal Fissures

  Tiny tears in the anal lining, often due to passing hard stools, can cause sharp pain and bleeding. Unlike haemorrhoids, fissures typically result in intense discomfort during bowel movements.

• Diverticular Disease

  Small pouches (diverticula) in the colon can become inflamed and bleed. While diverticular bleeding is usually painless, it can be sudden and heavy.

• Inflammatory Bowel Disease (IBD)

  Conditions like ulcerative colitis and Crohn’s disease lead to chronic inflammation in the digestive tract, causing ulcers and bleeding. This is often accompanied by abdominal pain, diarrhoea, and weight loss.

• Haemorrhoids or Piles

  Swollen veins in the rectum or anus can rupture, leading to fresh, bright red blood, often noticed on toilet paper or in the bowl. Chronic constipation, straining, or prolonged sitting can contribute to their formation.

• Colorectal Polyps and Cancer

  Precancerous growths (polyps) in the colon may bleed intermittently. If left unchecked, they can develop into colorectal cancer, a leading cause of gastrointestinal bleeding, often presenting with persistent rectal bleeding and changes in bowel habits.

Distinguishing Between Piles and Colorectal Cancer

Given that both hemorrhoids and cancer can manifest as rectal bleeding, medical evaluation is essential for accurate differentiation. If rectal bleeding occurs without known haemorrhoids or persists despite haemorrhoid treatment, further diagnostic testing is necessary to rule out colorectal cancer.

Symptoms

• Pain: Haemorrhoids cause pain, itching, and discomfort, especially during bowel movements, whereas colorectal cancer pain may present as frequent gas pains or cramps.
• Bleeding: Haemorrhoid bleeding is typically bright red and appears on toilet paper or in the bowl, whereas colorectal cancer may cause darker, tarry stools or bleeding mixed with stool.
• Other Symptoms: Colorectal cancer often presents with systemic symptoms such as unexplained weight loss, persistent fatigue, and anaemia, which are not typically associated with haemorrhoids.

Risk Factors

• Age: Haemorrhoids are common in young adults, while colorectal cancer is generally more prevalent after 50.
• Lifestyle Factors: Haemorrhoids are strongly linked to bowel habits and pressure on rectal veins, whereas cancer risk is influenced by genetics, age, and lifestyle choices like smoking and diet.
• Diet: A low-fibre diet is a major factor in both conditions, but for colorectal cancer, processed meat and high-fat diets also contribute.

Diagnosis

Haemorrhoids are often diagnosed through a simple physical examination. In contrast, diagnosing colorectal cancer usually involves more extensive tests such as a colonoscopy, biopsy, or imaging studies.

Colonoscopy is a key tool for detecting colorectal cancer and is generally not required for haemorrhoids unless symptoms persist or worsen despite treatment. If bleeding, discomfort, or other symptoms continue, further investigation—including colonoscopy—is important to rule out more serious conditions like colorectal cancer.

When to See a Doctor?

While minor rectal bleeding from haemorrhoids or fissures might subside spontaneously, persistent, heavy, or unexplained bleeding necessitates immediate medical attention. Similarly, symptoms like unexplained weight loss, persistent abdominal pain, or changes in bowel habits warrant prompt evaluation, as they could indicate a serious underlying condition, including colorectal cancer.

If you experience symptoms of both piles and cancer, particularly heavy rectal bleeding, seek immediate medical attention. Contact our clinic today at 6443 1005 to book a consultation with our colorectal surgeon in Singapore.