Blood In Stool

What Are The Possible Causes of Blood in Poop

Max. D Gray
By Max. D Gray. Updated: July 3, 2017
What Are The Possible Causes of Blood in Poop

Blood in the stool is often for many people an important warning sign. However, before you start frantically worrying, you need to determine whether this is a one-off or whether this condition has occurred repeatedly and intensely, which could indicate the presence of a digestive problem. In these cases, seeing a doctor is essential to get an accurate diagnosis.

However, in this article we explain the most common causes of this problem to help you answer the question why do you have blood in your stool. Read on and find out the most common reasons.

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  1. In these cases there is no cause for concern
  2. Haemorrhoids
  3. Anal fissures
  4. Stomach conditions
  5. Intestinal conditions
  6. Haemorrhages
  7. The importance of consulting a doctor

In these cases there is no cause for concern

Blood in the stool or color changes are conditions that should, almost always, trigger a medical consultation. However, there are cases where there is no cause for concern unless the situation arises frequently. Some of them are:

  • After a bowel movement which has required a lot of effort.
  • When the movement has been too hard and has caused damage in the rectum when coming out.
  • In cases of constipation, especially in children where a little blood in the stool can be considered normal. In this case it is important to take steps to fight constipation and consult a gastroenterologist if necessary.
  • When women are menstruating it is common for there to be some blood in the stool but there is no reason to worry.
  • If you've eaten foods such as liquorice, beetroot, tomatoes or any dark ingredient, it is also possible that your stools change colour. See how things develop and if it persists, contact your doctor.
What Are The Possible Causes of Blood in Poop - In these cases there is no cause for concern


When the stool is covered with bright red blood it is very possible that the problem is due to the presence of haemorrhoids, a fairly common condition that causes great discomfort to patients who have it. They can be classified into two types: internal and not always easy to detect or external and easier to identify.

In our article on haemorrhoids, we explain the most common signs of this condition. If you suffer from this disease, it is important to make changes in your routine that will help to prevent them. You can also apply some home remedies to relieve yourself while you follow your doctor's instructions.

What Are The Possible Causes of Blood in Poop - Haemorrhoids

Anal fissures

Anal fissures are common conditions that particularly occur in patients with inflammatory bowel disorders, such as ulcerative colitis or Crohn's disease or severe gastroenteritis, but also in those who suffer from frequent diarrhoea or have very hard stools that when being expelled could cause damage. It is also a common condition in infants and young children.

Consulting a doctor if you suffer changes in your stool is important to determine whether there is any digestive condition that needs to be attended to. In our article on how to treat anal fissures we give you the key points to reduce discomfort.

What Are The Possible Causes of Blood in Poop - Anal fissures

Stomach conditions

There are some conditions that affect the stomach which can lead to blood in the stool. The most common ones are:

  • Bleeding ulcers.
  • Gastritis.
  • Varicose veins in the stomach.

In these cases it is common for blood in the stool to cause the bowel movements to be black or very dark, which is known as melaena. This is the reason why a change in the colour of your stool is a sign that you cannot ignore.

What Are The Possible Causes of Blood in Poop - Stomach conditions

Intestinal conditions

Various intestinal diseases may be the reason why you have blood in your stool. In this case, the movements are usually covered with bright, red blood which is very easy to identify.

The most common disorders that can lead to this condition are:

  • Ulcerative colitis.
  • Crohn's disease.
  • Intestinal infections, various parasites and bacteria can lead to blood in the stool.
  • Diverticulosis.
  • Polyps in the intestine.
  • Bowel cancer.
  • Intestinal ischemia or interruption of blood flow to the intestine.
What Are The Possible Causes of Blood in Poop - Intestinal conditions


Gastrointestinal bleeding that occurs higher up, such as in the stomach or oesophagus, can lead to the presence of blood in the stool, causing them to turn dark and almost black. This may be due to the presence of ulcers, hernias or varicose veins in this area.

The importance of consulting a doctor

Because the causes of blood in the stool are so varied and it may be due to serious conditions, such as gastric bleeding or intestinal cancer, consulting a gastroenterologist as soon as possible for a diagnosis is essential. Even if you suspect that it is caused by haemorrhoids, frequent diarrhoea or intestinal inflammation, consulting a specialist is essential to receive an accurate diagnosis and timely treatment for the condition in order to ensure your health and wellbeing.

This article is merely informative, oneHOWTO does not have the authority to prescribe any medical treatments or create a diagnosis. We invite you to visit your doctor if you have any type of condition or pain.

If you want to read similar articles to What Are The Possible Causes of Blood in Poop, we recommend you visit our Diseases & secondary effects category.

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What Are The Possible Causes of Blood in Poop