Blood in faeces: Before freaking out, read on

You’ll know when there’s blood in your faeces or stools when the water in the toilet bowl turns a little red or when there are smears of red on the toilet paper you wipe yourself with.

Regardless, rectal bleeding alarms most, if not all people. But before panicking, understand that there are non-life-threatening causes in most cases of bleeding through the rectum.

However, there are also serious, life-threatening causes of rectal bleeding that warrant urgent attention and investigation by a doctor.

Less serious causes of blood in faece

  • Anal Fissure

One of the most common causes of rectal bleeding that many have experienced at some point in their lives is anal fissures.

Anal fissures refer to either a tearing or cut on the lining of the mucosal surface of the anus. This delicate surface, when torn, can be painful and bleed.

The pain may be severe when passing motion and may last for several hours after that.

Anal fissures can occur at any age albeit more common in infants and middle-aged adults. It can happen due to a few reasons which include:

  • Passing large or hard stools
  • Constipation and straining during bowel movements
  • Chronic diarrhoea
  • Anal intercourse
  • Childbirth


Haemorrhoids or piles, are swollen blood vessels in the rectum or anus. In many cases, haemorrhoids don’t cause symptoms.

However, when it does exhibit symptoms and signs, it can be painful, itchy, and sometimes cause bleeding.

Painless rectal bleeding with a bowel movement is a common symptom of haemorrhoids. Bright red blood typically coats the stools or blood may drip into the toilet or stain toilet paper.

Typical features of haemorrhoids include:

  • Bleeding after passing a stools – blood is usually bright red.
  • Itchy anal opening.
  • A lump hanging outside of the anus, which may need to be pushed back in.
  • A mucus discharge after passing stools, leading to feelings of discomfort.
  • Soreness, redness and swelling around the anus.

More serious causes of blood in faeces

  • Ulceration

Ulceration of the stomach usually does not result in the presence of obvious or rank blood in the stools because of the relatively longer transit time and journey the blood goes through before it passes out of the gastrointestinal system.

Usually, because of the delay, blood from the ulceration of the lining of the stomach will already be oxidised within the stools, causing the colour of the stools to be extremely dark, described as dark-tarry stools.

Doctors describe stools like these, accompanied by an awful stench, as “melena”. However, should the bleeding from the ulcer be overwhelming, some rank blood may be visible as well.

Ulcerations can be caused by a number of reasons, most commonly from frequently skipping meals, then consuming spicy, hot and acidic food after.

Ulceration can also be due to a form of gastrin-secreting tumour, known as Zollinger-Ellison Syndrome.

Regular consumption of NSAIDs analgesics can also result in a tendency to bleed as it interferes with the protective mechanisms of the stomach lining.

Inflammatory Bowel Diseases (IBDs)

Inflammatory Bowel diseases includes Crohn’s disease and Ulcerative Colitis.

These conditions cause chronic relapsing inflammation of the bowel, the gastrointestinal system as well as some extra-intestinal manifestation.

It is caused by a complex interaction between genetic predisposition, immune dysregulation targeted towards intestinal microbiota, and certain environmental factors.

IBDs can be very debilitating and because of the transmural inflammation or the surface ulceration of the bowel, bleeding can occur and lead to the presence of blood in the stools.

IBDs also increases one’s risk of developing bowel cancer especially for Ulcerative Colitis.

Bowel Polyps

Bowel polyps, also known as colon polyps, are small growths of tissue on the wall of the colon (large bowel) or rectum. Most polyps are small, usually less than 1cm in size, although they can grow larger.

Polyps can appear in many forms: they may look like a small raised lump, a wart, a grape or a mushroom on a stalk or a cluster of many small bumps. Some people have just one polyp, while others have several.

Most polyps are harmless and in most cases, polyps do not cause any symptoms and are often discovered by accident. However, over time some can develop into bowel cancer.

Polyps are usually removed if found as it grows into the lumen of the bowel and stands in the way of faecal movement causing rectal bleeding during the process of passing out stools.

Diverticular diseases

Diverticulars are pouches which bulge out of weak areas along the lining of the intestine wall. Usually small and shaped like a balloon, the contents of the bowel may accidentally get trapped inside these pouches.

Most diverticula don’t cause any symptoms (often referred to as Diverticulosis) but when it does, Diverticular disease is typically associated with pain in the lower left side of the abdomen or, less commonly, the right side.

It can also lead to bloating, constipation or diarrhoea and especially for Diverticulitis (when the diverticula becomes inflamed), cause bleeding.


Last but not least, the most worrying and life-threatening explanation as to why there is blood in the faeces is none other than cancer.

The suspicion of Bowel cancer (Colorectal cancer) is a possibility if you also experience chronic unexplained weight loss and chronic episodes of alternating diarrhoea and constipation.

The presence of blood in the faeces is not something you see every day. So if you have risk factors for the conditions explained above, or are worried about what the underlying cause could be, see a doctor immediately.

This article first appeared in and was reviewed by the Hello Doktor Medical Panel. The Hello Health Group does not provide medical advice, diagnosis or treatment.