Hi,
Welcome to hcm.
Diarrhoea for 2 days with headache probably due to infective cause.
Parasites bacteria usually cause diarrhoea.
It may be due to food poisioning, water borne.
Moving objects in stool may be parasites usually pinworm is of that size.
But severe diarrhoea is not due to it.
In diarrhoea lots of fluid loss occurs.
Plenty of fluid in sips in the form of
ORS, plain water, and rice water should be taken throughout the whole episode.
You should have a stool examination & proper medication.
For headache
paracetamol can be taken.
Metronidazole 400mg thrice daily for 3-5 days can be taken.
It will only kill the parasites not bacteria.
After the episode is over deworming should be done.
After these general measures if it persists consult a doctor.
Good luck.