Stress ulcers are caused by any area in the stomach that receives a reduced blood flow causing that area to ulcerate due to acid erosion of the area.
This is generally caused by prolonged sympathetic nervous system “flight or fight” responses. We give Pepcid and other Acid blockers as standard therapy to prevent stress ulcerations caused by literally the stress of being in the hospital, as well as chemical “flight or fight” reactions caused by IV or oral glucocortical steroids.
Certain bacteria have been implicated but not totally proven in ulcer formation; it is likely that they are oppotunistic and infest ulcers already formed, worsening the process.