There is basically one symptom of<unk> : bleeding from the area where the stomach lesion is. Bowel movements may contain blood. Vomit may be bloody as well, but a<unk>  may not cause vomiting. Blood may be black because it will be partially digested. Loss of blood may cause one to develop anemia.
Gastric erosion
Gastric volvulus
Perforated ulcer
Evisceration 
Atrophic gastritis
Tropical ulcer
Black stomach
Gastric lymphoma