Gastrointestinal bleeding could be caused from number of gastrointestinal diseases, including inflammation, infection and malignancy and it is a common symptom that needs immediate attention. Blood from the gastrointestinal track could in the form of black or tarry stool, blood in vomit or stool or could be microscopic and difficult to see. A number of tests including endoscopies, like EGD and colonoscopy and imaging studies will help localise the lesion. Treatment depends on the type of lesion found.