Important: This page is for general information only and is not a diagnosis. If you are worried about a symptom, please see a doctor.

What does blood in the stool mean?

Finding blood in the stool — or noticing bleeding from the back passage — is always worth taking seriously, even though it is usually caused by a benign (non-cancerous) condition. The blood can appear in different ways, and understanding the difference helps you describe your symptom clearly to a doctor:

  • Bright red blood — fresh blood that coats the stool, drips into the toilet bowl, or appears on toilet paper after wiping. This type most often comes from the lower bowel, rectum, or anus — common causes include haemorrhoids (piles) and anal fissures.
  • Dark red or maroon blood mixed into the stool — suggests bleeding from higher up in the large bowel (colon).
  • Black, tarry stool (melena) — dark, sticky, foul-smelling stool that looks like tar. This indicates bleeding from the stomach or upper gastrointestinal tract and always requires urgent evaluation.

Piles (haemorrhoids) — very common but not always the answer

Haemorrhoids (piles) are swollen veins inside or around the back passage. They are extremely common in India and are a very frequent cause of rectal bleeding. Bright red blood after passing stool, itching, and discomfort around the anus are typical features of piles.

However, piles are often self-diagnosed without any examination, and this carries a real risk: symptoms of colorectal cancer — including rectal bleeding — can look very similar to piles, especially in the early stages. A doctor must examine you to be sure. Do not assume bleeding is from piles without getting checked, especially if you are over 40.

When is rectal bleeding a warning sign for cancer?

Rectal bleeding or blood in the stool is one of the warning symptoms of colorectal cancer (cancer of the colon or rectum). The following features make it more likely to need urgent evaluation:

  • Blood in the stool that has continued for more than 2 weeks
  • Dark red or black tarry stool, or blood mixed through the stool (not just on the surface)
  • Change in bowel habits — stools that are narrower than usual, persistent diarrhoea or constipation lasting more than a few weeks, or a feeling that the bowel has not emptied completely
  • Unexplained weight loss — losing weight without trying
  • Abdominal pain or cramping that has appeared alongside the bleeding
  • Unexplained tiredness or anaemia — low haemoglobin found on a blood test, which can result from ongoing slow bleeding
  • Age over 40 with any rectal bleeding, especially with no obvious cause like known piles
  • Family history of colorectal cancer or polyps (growths in the bowel)

Gallbladder cancer note

In the Bihar and eastern Uttar Pradesh belt, gallbladder cancer has an unusually high incidence — one of the highest in the world. While gallbladder cancer does not typically cause rectal bleeding, it can cause right-sided abdominal pain, jaundice (yellowing of the skin or eyes), and nausea. If you have these symptoms alongside digestive complaints, mention them to your doctor as well.

Other possible causes

Most cases of rectal bleeding are not cancer. Common causes include:

  • Haemorrhoids (piles) — the most common cause; bright red blood, often after straining
  • Anal fissure — a small tear in the skin around the anus; causes pain and bright red blood
  • Diverticular disease — small pouches in the colon wall that can bleed
  • Inflammatory bowel disease — conditions like ulcerative colitis or Crohn’s disease cause bloody diarrhoea and cramping
  • Infections — certain gut infections cause bloody stools along with fever and diarrhoea
  • Polyps — non-cancerous growths in the bowel that can bleed; some polyps can become cancerous over time

Warning signs that need prompt attention

See a doctor the same day or go to an emergency department if you have:

  • A very large amount of rectal bleeding, or bleeding that does not stop
  • Black, tarry stool (melena)
  • Rectal bleeding with dizziness, faintness, or a rapid heartbeat

See a doctor within 1 week if you have:

  • Blood in the stool for more than 2 weeks
  • Blood in the stool with unexplained weight loss, change in bowel habits, or significant abdominal pain
  • Age over 40 with any new rectal bleeding and no established diagnosis

What tests a doctor will recommend

  1. Physical examination — including examination of the abdomen and a digital rectal examination (the doctor gently feels inside the back passage with a gloved finger to check for growths or abnormalities)
  2. Stool test for occult blood — a simple laboratory test that detects blood in the stool even when it cannot be seen with the naked eye. Often available at government hospitals and labs across Bihar
  3. Colonoscopy — a thin flexible camera is passed through the rectum to examine the entire colon. It is the gold standard test and can both detect and remove polyps in the same procedure. Colonoscopy requires bowel preparation (clearing the bowel beforehand) and mild sedation
  4. Sigmoidoscopy — a shorter version of colonoscopy that looks at only the lower part of the colon; more widely available than full colonoscopy
  5. Blood tests — full blood count (CBC) to check for anaemia, and liver function tests if gallbladder involvement is suspected
  6. CT scan or ultrasound — if the doctor suspects a mass in the abdomen

Access to endoscopy in Bihar

Colonoscopy access outside Patna is limited in Bihar. If you are in a district town, the first step is to visit the government district hospital or a surgeon who can examine you and decide whether a referral for colonoscopy is needed. Do not delay the first visit while waiting to find a colonoscopy centre — a physical examination and basic tests can already provide important information.

Where to get help in Bihar

  • Mahavir Cancer Sansthan, Phulwarisharif, Patna — has oncology and surgical gastroenterology; colonoscopy and colorectal cancer evaluation available
  • AIIMS Patna — gastroenterology outpatient department; colonoscopy, biopsy, and staging scans
  • Government medical colleges (PMCH, DMCH Darbhanga, JLNMCH Bhagalpur) — surgical OPD can evaluate rectal bleeding and refer appropriately

See our full hospital directory at /find-care/hospitals/.

For guidance on where to go, call the Indian Cancer Society helpline: 1800-22-1951 (free). For emergencies, call 108 or 112.