<unk>  is a condition that results from acute gastric necrosis. The tarry<unk>  colour is produced by the coagulative necrosis of mucosa resulting in intramucosal haemorrhage and acid hematin deposition. This condition was first described in a patient with acid poisoning. A similar condition has been described in acute esophageal necrosis due to mucosal ischemia resulting from hemodynamic compromise.
Black stomach
Phytobezoar
Magic string 
Gastric volvulus
Retained antrum syndrome
Tonsil stones
Pyloric stenosis
Megaesophagus