As far as I know, words are utterly ineffective against diarrhea. You might try a antidiarrheal instead.
An antagonist counteracts another medication.
A fail-safe is a backup feature that that counteracts a failure in a system.
Suguar.
An antidepressant is a medicinal drug used to treat depression.
what counteracts naproxen
An anticoccidial is a substance which counteracts coccidiosis.
An antihysteric is a substance which counteracts hysterics.
Gravity counteracts this inertia, usually the gravity of a body much larger than itself.
An antihypertensive is an agent which prevents or counteracts hypertension.
An antimalarial is an agent which prevents or counteracts malaria.
An antinephritic is a remedy which counteracts diseases of the kidneys.