Final answer:
After gastric bypass surgery, a small pouch is formed and the jejunum is directly attached to it, bypassing the stomach and the duodenum. This change affects the movement of chyme from the stomach to the intestine at the jejunum. The result is limited food intake and nutrient absorption, leading to weight loss.
Step-by-step explanation:
After gastric bypass surgery, the main section of the stomach is closed off from the digestive tract and a small pouch is formed. The jejunum is directly attached to this pouch, bypassing the stomach and the duodenum. This significant anatomical change affects the movement of chyme from the stomach to the intestine at the jejunum.
Instead of flowing through the usual pathway of the stomach and duodenum, chyme now enters the small intestine directly through the jejunum. This bypass limits the intake of food and the absorption of nutrients, resulting in weight loss.