Gastric bypass surgery is also known as Roux-en-Y gastric bypass, is a weight-loss surgery involving rearranging the stomach and small intestine to limit food intake and absorption. The procedure works by:

1. Reducing the stomach size, creating a small pouch that can hold only a small amount of food.
2. Re-routing the small intestine, bypassing a portion of it, to reduce nutrient absorption.

Gastric bypass surgery is typically recommended for individuals with severe obesity (BMI ≥ 40) or those with obesity-related health conditions, such as type 2 diabetes, high blood pressure, or sleep apnea.