Disclosed are embodiments of an apparatus and system for performing a sleeve gastrectomy. The apparatus can include a bougie for insertion into an interior of a stomach, the bougie having a proximal bougie end and a distal bougie end, an inflation lumen having a proximal lumen end and a distal lumen end, the inflation lumen extending from the proximal bougie end through the distal bougie end, a fluid delivery system coupled with the proximal lumen end, the fluid delivery system being operably configured to deliver positive pressure in a predetermined positive pressure range into the stomach, and a monitor coupled with the proximal lumen end operably configured for the monitoring of pressure or volume within the stomach. The bougie can be operably configured to define a resection line for the sleeve gastrectomy when the predetermined positive pressure range is achieved within the stomach.