After 1 hour pooling of the barium was again noted in the proximal jejunum, which appeared somewhat dilated. At 6 hours (Fig. 1) the stomach had emptied, but a residue of barium was still present ...

and the Roux limb of the proximal jejunum is connected to the stomach pouch via a gastrojejunal anastomosis, bypassing the entire duodenum. The remaining portion of the proximal jejunum is ...

Surface area for drug absorption The villi and microvilli responsible for the vast absorptive surface in the small intestine are of highest concentration in the duodenum and proximal jejunum.