- Peptic ulcers: These are open sores in the stomach or duodenum caused by Helicobacter pylori infection or the use of non-steroidal anti-inflammatory drugs (NSAIDs). The ulcers can erode into blood vessels, leading to bleeding.
- Oesophageal varices: These are swollen veins in the oesophagus, commonly seen in individuals with advanced liver disease. If these veins rupture, they can result in significant and sudden bleeding.
- Diverticulosis or diverticulitis: Small bulges or pouches in the colon wall can become inflamed or damaged, leading to bleeding, which may be mild or profuse.
- Gastrointestinal tumours: Benign or cancerous growths in the stomach, intestines, or rectum may bleed intermittently or consistently, depending on their size and location.
- Inflammatory bowel disease (IBD): Conditions such as Crohn’s disease or ulcerative colitis can cause inflammation and ulcers, leading to bleeding within the gastrointestinal tract.
Gastrointestinal Bleeding

Dr Chong Choon Seng
MBBS | MRCS | Masters in Medicine (Surgery) | FRCS (Edinburgh)
Gastrointestinal (GI) bleeding refers to blood loss that occurs within any part of the digestive tract, ranging from the oesophagus to the anus. This condition can present with visible signs such as vomiting blood or black stools, or it may be detected through symptoms related to blood loss, including fatigue or dizziness. The severity can vary from minor to significant bleeding that requires immediate medical intervention.




Symptoms of Gastrointestinal Bleeding
Gastrointestinal bleeding may present with various symptoms, some of which can indicate the location or severity of the bleed. Common symptoms include:
- Vomiting blood: This symptom can range from bright red, fresh blood indicating active bleeding to a coffee-ground appearance, which suggests partially digested blood from the stomach.
- Black, tarry stools: Dark, sticky stools with a foul smell often point to bleeding in the upper digestive tract, as the blood has been partially digested during its passage.
- Blood in stool: Fresh blood in the stool typically suggests a source of bleeding in the lower digestive tract, such as the colon or rectum.
- Anaemia-related symptoms: Chronic blood loss may result in fatigue, pale skin, dizziness, and shortness of breath as the body struggles to maintain adequate red blood cell levels.
- Abdominal pain or discomfort: This can occur when bleeding is caused by ulcers, inflammation, or other underlying conditions that irritate or damage the digestive tract lining.
Causes and Risk Factors
Several underlying conditions and lifestyle factors can contribute to gastrointestinal bleeding. Common causes and risk factors include:
Types of Gastrointestinal Bleeding
Gastrointestinal bleeding is categorised based on its location within the digestive tract, as this affects its symptoms, underlying causes, and treatment options. The main classifications are:
Upper gastrointestinal bleeding
This type occurs in the oesophagus, stomach, or duodenum. Common causes include peptic ulcers, oesophageal varices, and gastritis. Symptoms typically include vomiting blood (haematemesis) and black, tarry stools (melena).
Lower gastrointestinal bleeding
This refers to bleeding from the small intestine, colon, rectum, or anus. Frequent causes include diverticular disease, haemorrhoids, or colorectal cancer. A common symptom is the presence of fresh red blood in the stool (haematochezia).
Occult bleeding
Occult bleeding involves blood loss that is not visible to the naked eye but can be identified through laboratory tests, such as a faecal occult blood test or as part of an evaluation for iron deficiency anaemia. It is often linked to chronic conditions such as slow-bleeding ulcers or tumours in the small intestine.
Diagnosis of Gastrointestinal Bleeding
Physical examination and medical history
A detailed history helps determine the nature of symptoms, any use of medications like NSAIDs, or the presence of risk factors such as liver disease or prior GI conditions. The examination may include checking for signs of anaemia or shock.
Endoscopy
An upper or lower endoscopy provides direct visualisation of the digestive tract, allowing for the identification and treatment of active bleeding. During the procedure, specialised tools may be used to cauterise or clip bleeding vessels.
Imaging studies
Imaging techniques such as CT angiography or radionuclide scans help locate bleeding sites that are not visible through endoscopy. These methods are particularly helpful in cases of active or intermittent bleeding.
Laboratory tests
Blood tests assess haemoglobin levels, clotting function, and potential infections. Tests like a faecal occult blood test can identify hidden blood loss, while crossmatching ensures the availability of blood for transfusions if necessary.
Treatment Options
Management of gastrointestinal bleeding depends on its cause, severity, and location. Treatment includes both non-surgical and surgical approaches aimed at controlling bleeding and addressing underlying conditions.
Non-Surgical Treatment
- Endoscopic Treatment Techniques: Endoscopic techniques are often the first-line treatment for active bleeding. A flexible tube with a camera (endoscope) is used to locate the bleeding site, and various tools can be employed during the procedure. Thermal coagulation applies heat to seal bleeding vessels, haemostatic clips physically close the source of bleeding, and injection therapy delivers substances like adrenaline to constrict blood vessels or promote clot formation. These methods are minimally invasive and can be repeated if necessary.
- Medications: Drugs are prescribed to target the underlying cause or reduce the risk of recurrent bleeding. Proton pump inhibitors (PPIs) lower stomach acid levels, allowing ulcers to heal and reducing irritation. Antibiotics such as those for Helicobacter pylori infection address specific triggers of ulcers. In certain cases, vasoactive drugs are used to reduce blood flow to areas like oesophageal varices, limiting further bleeding.
- Replenishing Iron and Blood Levels: For significant blood loss, treatment focuses on restoring haemoglobin levels and addressing deficiencies. Blood transfusions provide immediate replacement for lost red blood cells, stabilising oxygen delivery in the body. In cases of chronic bleeding, iron supplementation is administered orally or intravenously to treat or prevent anaemia. Careful monitoring ensures adequate recovery without complications.
Surgical Treatment
- Resection of Affected Areas: When bleeding persists despite non-surgical methods, surgery may be necessary to remove the damaged portion of the digestive tract. A section of the stomach or intestines with a bleeding tumour, severe ulceration, or diverticular disease may be excised. This approach is typically reserved for severe or life-threatening cases, especially when other interventions have failed.
- Vascular Repair or Bypass: In cases where bleeding stems from damaged blood vessels or vascular abnormalities, surgery may involve repairing the vessel directly or rerouting blood flow to bypass the affected area. For example, a ruptured aneurysm or arteriovenous malformation may require surgical intervention to stop bleeding and restore normal circulation. This approach reduces the risk of recurrent bleeding and stabilises the patient.
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Prevention and Management
Preventive measures for gastrointestinal bleeding include managing underlying conditions, avoiding excessive use of medications like NSAIDs, and limiting alcohol intake. Eating a balanced diet and addressing symptoms early can also reduce the risk of complications. Individuals with known conditions, such as peptic ulcers or liver disease, should follow their treatment plans and attend regular check-ups to monitor for signs of recurrence.
Frequently Asked Questions
What is the likelihood of recurrence after treatment for gastrointestinal bleeding?
Recurrence depends on the underlying cause and management of risk factors like H. pylori infection or NSAID use. Conditions such as peptic ulcers or varices may require ongoing treatment and regular follow-up to reduce the risk.
Can chronic gastrointestinal bleeding lead to other complications?
Yes, prolonged bleeding can cause iron deficiency anaemia, weakened immunity, and heart strain due to reduced oxygen levels in the blood. Early treatment prevents these complications.
Can gastrointestinal bleeding be triggered by exercise?
Rare but intense physical activity, especially endurance sports, can cause minor GI bleeding (“runner’s gut”) due to reduced blood flow and irritation. Frequent symptoms should be medically evaluated.
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Dr Chong Choon Seng
MBBS (NUS)
MRCS (Edinburgh)
Masters in Medicine (Surgery)(NUS)
FRCS (Edinburgh)
Dr Chong is the former Program Director of General Surgery Residency at NUHS, and has more than 10 years of experience as a colorectal and general surgeon.
As an esteemed professional in minimally invasive surgery, Dr. Chong remains committed to achieving optimal outcomes for all surgical conditions, from piles to cancer treatment.
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