Thanks for posting your query.
With the available described symptoms, there could be possibility of acute bacterial gastroenteritis
Frequent urge for defecation but not getting anything is suggestive of diagnosis.
You should consult with internal medicine specialist/ general surgeon
and should go for thorough check up.
You should also go for complete blood count
imaging, and serum electrolytes.
You should take complete antibiotic therapy, antispasmodics, probiotics, antipyretics, if needed.
You should maintain your hydration by taking potassium rich liquids.
Avoid milk and all milk related products.
There appears to be least correlation between Roacutane and present symptoms.
Dr. Mayank Bhargava