A posteriorly perforating ulcer in the pyloric antrum of the stomach is likely to produce initial localized peritonitis or abscess formation in the
Stomach rupture posteriorly causes peritonitis or abcess formation in lesser sac or omental bursa whereas rupture anteriorly causes abscess formation in greater sac whereas in supine posture abcess formation occurs in pouch of Morison which is dependent pa of stomach.
Greater sac
Right subhepatic/hepatorenal space (pouch of Morison)
Omental bursa
Right subphrenic space
Stomach and aerial supply of abdomen