Thanks for posting your query.
With the available described symptoms, there appears possibility of acute viral upper respiratory tract
infection with gastrointestinal involvement.
Presence of cold, cough and nasal congestion
suggests the diagnosis.
You should consult with internal medicine specialist/ chest physician and should go for thorough check up.
He should go for complete blood count
, erythrocyte sedimentation rate
and chest x ray.
He should take complete antibiotic therapy, decongestants, mucolytics and cough suppressants.
For loose motion, he should take probiotics and antispasmodics if abdominal pain
He should void milk and all milk related products.
He should maintain his hydration status by taking potassium rich supplements.
Dr. Mayank Bhargava