This is a UKMLA-centred history guide about melaena.
Introduction
Melaena is a common complaint seen in patients presenting to general practice and the ED, as well as with inpatients in secondary care.
Melaena is black, tarry stool, and is typically very foul-smelling. It is associated with significant upper GI bleeding, and is evidence of digested haemoglobin in the digestive tract.
The presence of melaena alone suggests upper gastrointestinal bleeding, but it does not tell you the precise cause. It is important to take a thorough history to narrow down the likely causes.
Presenting Complaint
Try to expand on the presenting complaint by asking the following questions:
- Timing – duration? constant? intermittent?
- Associated symptoms – melaena may be accompanied with or without abdominal pain. Haematemesis may also be present as well as reduced appetite. Coffee-ground vomiting increases the likelihood that it is indeed an upper GI bleed. The coffee-ground appearance is due to the digestion of blood in the upper GI tract.
- Precipitating factors?
- Anything make it better?
- Anything make it worse?
Common Causes of Melaena
It is important to demonstrate to the examiner that you are aware of these common causes and establish which system to click into.
Background
In any history you will ask about past medical history, medications, allergies, social history, and family history. In a history about melaena you can show how much you know about the various causes by explicitly asking about the following things:
Past Medical History
Key questions to ask include:
- Does the patient have frequent bleeding problems such as nosebleeds, haematuria or excessive bleeding from cuts? Any possibility of coagulation disorder?
- Does the patient have a history of acute coronary syndrome, stroke or vascular disease, which is suggestive of antiplatelet treatment? These increase the risk of bleeding and may be suspended if bleeding is evident.
- Is the patient on a direct oral anticoagulant (DOAC), such as apixaban or edoxaban? These are commonly prescribed for atrial fibrillation.
- Do they have a metal valve or other implant necessitates anticoagulation (e.g. with warfarin).
- What is the mental health history of the patient? Are they on anti-depressants? SSRIs such as sertraline are associated with increased risk of upper GI bleeding.
- Does the patient have a history of gastrointestinal malignancy or risk factors?
- Does the patient have liver problems? The liver produces coagulation factors. Someone who has liver failure may not be able to produce coagulation factors normally. Liver cirrhosis causes portal hypertension, which causes varices to develop at sites of porto-systemic anastomosis. Oesophageal varices are at risk of rupturing, leading to catastrophic bleeding.
- Is there a possibility of Mallory-Weiss syndrome (i.e. recent forceful vomiting)? Are there any signs of bulimia nervosa (e.g. Russell’s sign, parotid enlargement)?
- History of reflux? Stomach acid can irritate the lining of the oesophagus and predispose to bleeding.
- Any recent abdominal surgery? Bleeding may be a complication of the surgery. Surgical opinion and correction may be needed in severe cases.
- Any history of severe burns of head trauma? Physiological stress from major burns can predispose to the development of a peptic ulcer due to mucosal ischaemia (Curling’s ulcer), while head injury, surgery or intracranial tumours can lead to the development of a peptic ulcer due to overproduction of gastric acid (Cushing’s ulcer).
- History of joint pain, rheumatological conditions or arthropathy? This can suggest frequent NSAID or steroids, which are common risk factors for peptic ulcer formation.
Drug History
The following drug groups may increase risk of upper GI bleeding
- NSAIDs e.g. ibuprofen, naproxen
- Steroids e.g. prednisolone, dexamethasone
- SSRIs e.g. sertraline, citalopram, fluoxetine
- Anticoagulants
- Drugs which affect liver metabolism in patients taking warfarin. Enzyme inhibitors of cytochrome P450 can increase the concentration of warfarin and therefore INR, predisposing to bleeding.
Family History
- Coagulation disorders (Haemophilias, Von Willebrand disease)
- History of cancer (e.g. MEN syndromes)?
- History of dyspepsia, symptoms of upset stomach, pain, indigestion, bloating. This can predispose to bleeding due to irritation of stomach/esophageal lining.
Social History
- Alcohol – increased risk of bleeding from varices from long-term excess intake, due to the development of portal hypertension from liver cirrhosis. Chronic use may also increase the risk of bleeding due to liver failure (decreased synthesis of clotting factors), as well as predisposing to gastric cancer.
- Smoking – increased risk of bleeding secondary to cancers in GI which can cause bleeding
- Occupation – lung cancer risk may be higher in certain individuals, it is known to metastasize to liver, and in severe cases cause liver failure, decreasing production of coagulation factors. (Less common but useful to keep in mind)
- Diet – can precipitate fatty liver disease
- Other – tattoos, hepatic viruses (risk is increased in IV drug users)
- Demographics can also play an important part:
- Age – suspicion of cancer is higher in older patients.
- Gender – males are 2-fold more likely to have gastric cancer than females, and more likely to have gastritis and peptic ulcers.
- Cultural background – rates of gastric cancer are highest in Eastern Asia
- IVDUs – more likely to contract hepatitis, leading to cirrhosis, portal hypertension and oesophageal varices
Author and Editor – Dr Tachakrit Tachatirakul Â
Last updated 29/01/2026
