From the symptomatology it seems like a case of Gastroentritis.
is condition characterized by inflammation of the gastrointestinal tract that involves both the stomach and the small intestine
, resulting in some combination of diarrhea
, vomiting, and abdominal pain
the black stools is mostly indicative of blood in the stools.
hence, the cause is less likely to be viral and more likely to be bacterial
The primary treatment of gastroenteritis is rehydration. This is preferably achieved by oral rehydration therapy
Oral replacement therapy products made with complex carbohydrates (i.e. those made from wheat or rice), ORS also is very good option.
Personal measures (such as hand washing) have been found to decrease incidence and prevalence rates of gastroenteritis
Gastroenteritis is usually an acute and self-limiting disease that does not require medication.
But if it does not resolve with the above measures you can start a course of antibiotics such as Tab . Azithromycin