All patients with a suspected acute lower GI bleed should be assessed as a matter of some urgency, as there can be significant mortality (up to 20%). [1,2,3]

A thorough history and examination are essential in order to:

  • Try and help identify the source of bleeding
  • Make some assessment as to the amount of bleeding which may have occurred
  • Ensure adequate resuscitation is instituted

Patients who present with acute lower GI haemorrhage often find it difficult to describe and may complain of passing bright red blood per rectum. It is useful to clarify the exact nature of the blood by the frequency, colour and the presence or absence of clots.

Melaena (dark tarry stool) generally indicates an upper GI or small bowel source, whereas fresh, red blood generally indicates bleeding from the left colon or rectum. However, it is important to remember that this is not always the case.

Other symptoms

Other symptoms (such as fatigue, chest pain, palpitations and shortness of breath) should be elicited along with any past medical history.

Certain symptoms may help to distinguish between inflammatory, infective and malignant causes, such as abdominal pain, weight loss, fever, diarrhoea or vomiting.

Medication use is also of relevance. In particular, the use of warfarin, heparin, NSAIDS and inhibitors of platelet aggregation can be important as some of these medications may require urgent reversal.