**1. Introduction**

Most of the gastrointestinal (GI) bleeding occurs from the upper and lower gastrointestinal tract. Mid-gastrointestinal (GI) bleeding refers to small bowel bleed anywhere from the ampulla of Vater to the ileocecal valve [1]. It occurs in 5–10% of all cases of gastrointestinal bleeding [2]. It is the most common cause of obscure GI bleeding, i.e., when the source of bleeding cannot be identified anywhere in the gastrointestinal tract [3, 4]. Management of mid-GI bleeding can be challenging to a gastroenterologist although various diagnostic and therapeutic tools are now available to evaluate and treat mid-GI bleeding. Despite the availability of various endoscopies and imaging studies, the exact cause of mid-GI bleeding can be still elusive in about one third of cases [5]. The etiology, clinical presentation, evaluation, investigations, and management of mid-GI bleeding will be discussed in this chapter.
