Listeriosis is a disease caused by infection with the bacterium Listeria monocytogenes, and it is most often contracted after eating contaminated foods or liquids. Listeriosis most commonly affects newborns, the elderly, pregnant women, and those individuals with a poorly functioning immune system (immunocompromised).
I have been on Plaquenil and can tell you my diarrhea started within days of starting the med. My doctor warned me that diarrhea and weight loss were side effects. I said, Well, I am usually very constipated and could stand to lose 10 pounds so this could be a good thing.. haha.
Use nonprescription antidiarrheal medicine if you have diarrhea for longer than 6 hours. Do not use nonprescription antidiarrheal medicines if you have bloody diarrhea, a high fever, or other signs of serious illness. Read and follow all label directions on the nonprescription medicine bottle or box.