Blood in the stools can be a frightening symptom for many people. However, it is important to know that, although it may be a sign of a serious illness, it is often caused by more harmless factors. The most important thing is not to ignore the symptom and to see a specialist as soon as possible to obtain an accurate diagnosis. In this detailed guide, we’ll look at what blood in the stool might indicate, the different types of blood that can appear, and what to do if you experience this symptom.
Forms in which blood may appear in the stools
The colour and appearance of blood can reveal a great deal about the source of the bleeding within the digestive system. We distinguish between three main types:
- Haematochezia (fresh, red blood): When we notice bright red, fresh blood in our stools or on the toilet paper, it usually originates from the lower digestive tract (large intestine, rectum). As the blood is not digested, it retains its bright colour.
- Meléna (Black, tar-coloured faeces): Black, tar-like, sticky stools with a characteristically unpleasant odour, containing digested blood. They most commonly originate from the upper digestive tract – the oesophagus, stomach or duodenum.
- Occult (hidden) bleeding: This bleeding is not visible to the naked eye. Its presence may be revealed by a laboratory faecal occult blood test or during investigations into iron-deficiency anaemia (fatigue, pallor).
Possible causes of bloody stools
1. Common causes affecting the lower gastrointestinal tract (fresh, red blood)
- Haemorrhoids (Nodus haemorrhoidalis): One of the most common causes. It is caused by damage to the dilated veins around the anus and is typically painless.
- Anal fissure (Analis fissura): A fissure in the skin accompanied by a sharp, stabbing pain, often caused by hard stools.
- Diverticulosis: Inflammation or bleeding from small protrusions that form on the wall of the large intestine.
- Inflammatory bowel diseases (IBD): Crohn’s disease and ulcerative colitis, which are characterised by chronic inflammation.
- Infectious colitis: Infections caused by bacteria (e.g. Salmonella, E. coli).
- Polyps and bowel cancer: Polyps may bleed and, over time, develop into malignant tumours. Bleeding is one of the main symptoms of bowel cancer, which is why it is vital to get checked!
- Angiodysplasia: Abnormally dilated, fragile capillaries in the intestinal wall (more common in older people).
2. Common causes affecting the upper gastrointestinal tract (black stools)
- Peptic ulcer disease (Pepticus ulcus): Stomach or duodenal ulcers, often Helicobacter pylori due to an infection or NSAID medication.
- Oesophagitis: It may be a consequence of severe reflux.
- Mallory-Weiss tear: A tear in the mucous membrane at the entrance to the stomach caused by violent vomiting.
- Oesophageal varices: A complication of liver disease that can cause life-threatening bleeding.
- Tumours: Oesophageal or stomach tumours.
When should you see a doctor IMMEDIATELY?
If certain accompanying symptoms are present, you must call an ambulance immediately (112) or go to A&E:
- Heavy, continuous bleeding.
- Dizziness, weakness, a feeling of faintness, pale, cold skin.
- Confusion, impaired consciousness.
- Severe, cramp-like abdominal pain.
- Vomiting blood (fresh red or coffee-ground-like).
Making the diagnosis
From Endomedix Gastroenterology Centre Its specialists use modern diagnostic methods to identify the source:
- Physical examination: Digital rectal examination to identify haemorrhoids and fissures.
- Laboratory: Blood test (to check for anaemia) and faecal occult blood test.
- Endoscopy (Gold Standard):
- Colonoscopy (colonoscopy): A full examination of the large bowel, including sampling and polyp removal.
- Gastroscopy (gastroscopy): Identification of sources in the upper reaches of the watercourse.
- Capsule endoscopy: For the examination of the hidden sections of the small intestine.
Treatment options and prevention
Treatment depends on the underlying cause (lifestyle changes, medication, polyp removal or surgery). To prevent the condition:
- A diet rich in fibre: Plenty of vegetables, fruit and whole grains.
- Fluid intake: 2–2.5 litres of water a day.
- Move: It stimulates bowel function.
- Medication monitoring: Use of NSAIDs (e.g. aspirin, ibuprofen) with caution.
- Screening test: in 2026 Screening colonoscopies for people aged 45–50 and over are the most effective way of saving lives!
Summary: Never ignore blood in your stools! Diseases detected early are much more likely to be cured. Please visit the Endomedix Gastroenterology Centre its specialist doctors for state-of-the-art examinations, including those carried out under anaesthesia.
