**Abstract**

Duodenal exclusion is used in surgery for multiple reasons. It can be used to treat primary pathology, such as with peptic ulcer disease, malignancy, gastric outlet obstruction, or after trauma. It is also used in metabolic surgery to add a hypoabsorptive effect for weight loss and beneficial impact on various co-morbidities. There are additional neurohormonal implications of duodenal exclusion that vary, depending on where the intestine is divided, and how long of a common channel or absorptive limb is left in place. Impact on diseases such as diabetes is mediated via complex pathways that continue to be researched today. Duodenal exclusion exhibits indisputable benefits but is linked to well-known side effects and complications. Understanding the physiological importance of the duodenum, the implications of its exclusion, the variety of methods for reconstruction and their impact is important in caring for these patients after surgery.

**Keywords:** duodenal exclusion, bariatric surgery, metabolic surgery, gastric bypass, duodenal switch, biliopancreatic diversion
