Here's a diagram of the food pump that's currently being developed in the U.S.
But according to Ars Technica, a variation of the food pump system that's in development in the U.S. is already offered in Europe by a company called Aspire Bariatrics:
Here are some screencaps from the non-embeddable video on the company's website of how the pump collects stomach contents.
From Aspire Assist's overview page, this is how their device works:
To begin Aspiration Therapy, a specially designed tube, known as the A-Tube™, is placed in the stomach. The A-Tube is a thin silicone rubber tube that connects the inside of the stomach directly to a discreet, poker-chip sized Skin-Port on the outside of the abdomen. The Skin-Port has a valve that can be opened or closed to control the flow of stomach contents. The patient empties a portion of stomach contents into the toilet after each meal through this tube by connecting a small, handheld device to the Skin-Port. The emptying process is called "aspiration".
