Thanks for posting your query.
With the available described symptoms, there appears to be possibility of acute viral gastroenteritis
Presence of foul smelling watery diarrhea, abdominal pain
and body ache
suggests the diagnosis.
Myalgia is a prodromal symptom of viral infection.
You should consult with internal medicine specialist and should go for thorough check up.
You should also go for complete blood count
, renal function test, serum electrolytes.
You should take complete antibiotic course, antispasmodics, robotics.
You should also take potassium rich fluid and oral rehydration solution.
You should also go for colonoscopy
to rule out colonic pathology as symptoms are persisting since long time.
Dr. Mayank Bhargava