Thank you for posting your query.
Headache in this case could be on account of viral infection, which is leading to loose stools as well as headache. Analgesics such as diclofenac
and ibuprofen can be used to relieve the headache.
If headache does not subside in a day or two, one should also exclude cerebral venous sinus thrombosis
(clotting of blood in brain veins). This can occur due to dehydration
(because of loose stools). A brain scan after consultation with neurologist
would be useful in excluding this condition.
Wishing you good health,
Dr Sudhir Kumar MD (Internal Medicine) DM (Neurology)