A posteriorly perforating ulcer in the pyloric antrum of the stomach is likely to produce initial localized peritonitis or abscess formation in the -
A posterior gastric ulcer may perforate into the lesser sac (omental bursa).
The leaking fluid passes out through epiploic foramen to reach the hepatorenal pouch.
Sometimes in these cases, the epiploic foramen is closed by adhesions.
Then the lesser sac becomes distended and can be drained by a tube passed through the lesser omentum.
Greater sac
Left subhepatic and hepatorenal spaces (pouch of Morrison)
Omental bursa
Right subphrenic space