A thorough physical examination is important to assess the amount of blood loss, the degree of shock and the possible source. It is important also in identifying any other medical conditions which may play a role in the morbidity and mortality, and potentially affect future investigations.
Initial observations (such as dyspnoea, tachypnoea, tachycardia and, in particular, postural drop in blood pressure) are important and may indicate more significant blood loss and shock.
The presence of abdominal tenderness on examination may help to suggest that the source of bleeding is more likely to be secondary to an inflammatory disorder, such as ischaemic colitis.
A PR examination must be performed in all those suspected of GI haemorrhage (not only to assess the stool colour, presence of blood and so on, but also to look for anorectal lesions).