A posteriorly perforating ulcer in the pyloric antrum of the stomach is most likely to produce initial localized peritonitis or abscess formation in the following:
Omental bursa (lesser sac)
Greater sac
Right subphrenic space
Hepato renal space (pouch of Morison)
Answer is A (Omentum bursa) "Gastric ulcers perforate into the lesser sac, which can be paicularly difficult to diagnose" - Bailey "A gastric ulcer perforates into the lesser sac, then no signs of generalised peritonitis can be seen but misleading symptoms may appear" - Schwaz As can be seen from the figure, a posteriorly perforating ulcer of the stomach will localize in the lesser sac or omental bursa only. (lesser sacis synonymous with omental bursa)