Thank you for the query.
Your boyfriend is most likely suffering of gastrointestinal infection
). It can be bacterial of viral. Great majority of such cases heals by its own and no doctors attention is necessary. He should drink plenty of liquids, avoid fried, spicy and fatty foods and he should be fine.
However if high fever
, blood in stool
will appear or the symptoms wont go away after 48 hours, he should consult a doctor and have stool tests done.
Hope this will help.