Stomal stenosis is one of the possible complications of gastric bypass (also known as weight loss or bariatric) surgery. It is seen generally in a type of weight-loss surgery called Roux-en-Y, one of the most common forms of gastric bypass.
Location

An anastomosis (connection) between the stomach and lower intestine is formed during gastric bypass surgery. This is the point at which stomal stenosis occurs.
Features

Stomal stenosis is a narrowing (stricture) of the new connection between the stomach and lower intestine, according to Dr. Janey S.A. Pratt of the Department of Surgery at Harvard University School of Medicine.
Causes

The overall cause of stomal stenosis in unknown, although it has been connected to too much scar tissue, problems with blood flow in the area, vomiting, ulcers and problems with surgical materials (banding or the contraction of stitching material), according to Dr. Pratt.
Considerations

The chances of stomal stenosis, according to Dr. Pratt, are linked to the type of technique used to suture the anastomosis, with circular staplers being likely to cause the condition and hand-suturing the anastomosis being the least likely to cause stenosis.
Symptoms

The symptoms of stomal stenosis include trouble swallowing, not being able to tolerate solid food, nausea and vomiting, according to Dr. Pratt.
Treatment

Treatment for stomal stenosis may require the dilation of the area with a tube inserted through the mouth or, sometimes, surgery, according to the Mayo Clinic.
Source:

"Roux-en-Y Gastric Bypass: Stomal Stenosis;" Dr. Janey S.A. Pratt; 2008
Mayo Clinic: Gastric Bypass Surgery Risks