hello dear, acids after ingestion damage the gastric mucosa
, which leads to ulcer formation .The other symptoms u have described, esp vomiting
is due to a gastric ulcer.
vomiting is in black clots because blood in stomach turns black due to gastric HCl, it turns into acid haematin.
Acid ingestion is an attempt to suicide
needs psychiatric evaluation too.
Take the patient to a good homoeopath.