Thanks for posting your query at DoctorSpring.com
I am Dr.R.K and I am pleased to assist you.
No zantrex 3 black may not be responsible for your symptoms.
You probably have a stomach bug.
A stool analysis may be done for confirmation.
You can take a course of probiotics for relief.
External hemorrhoids will not go on its own. It has to be removed surgically.
I hope that answers your question.
Let me know if I can assist you further.
Dr. R. K.