The pylorus is the valve at the end of the stomach through which ground up food passes. At times, the pylorus will become narrowed and fixed so that food does not readily get out of the stomach. Image 1 shows a fixed tight pylorus. It is the black hole in the image. A sausage-shaped balloon was put through this narrowing and then inflated as seen in Image 2. It resulted in a planned tear in the valve, making the opening larger and correcting the problem, as shown in Image 3.