Hi Dear the symptoms you are mention are strongly pointing towards sever gastroenteritis
,that is infection of gastro intestinal tract.the undigested food your passing is due to increased peristalsis
(gut motion). and stomach pain is due to increased acid in the stomach,all these are associated with gastro entritis.don't worry take a course of antibiotic in the form of oflox ornidazole
along with pentoperizole.and plenty of fluids.for nausea
anti emetics can be taken in the form of onendenosterone.relax it will settle in 2 to 3 days time.