As per my advise,your child needs immediate visit to a pediatrician
.He needs to undergo proper checkup so as to rule out the cause of loosemotion and associated abdominal pain
will help in lowering down his fever
but not stomachache.Any antispasmodic shall help him.As for your son talking things, making no sense,well happens in high grade fever....which your son might be having that moment.Anyways my advise,never let temperature reach higher than (100).Nothing to worry as such it could just be a case of gastro enteritis
,so visit the concerned doctor.Give him light food,plenty of fluid to maintain his hydration and that shall do good.so take care dear.