Drugs versus Biologics. 1  A biologic is manufactured in a living system such as a microorganism, or plant or animal cells. 2  Most biologics are very large, complex molecules or mixtures of molecules.enerics Drugs versus Follow-On Biologics. 1  To be approved as a generic, a drug must have the same active ingredient, strength, dosage form, and route of administration as the reference drug, and it must also be bioequivalent..
Viruses (e.g., adenovirus, astrovirus, rotavirus, Norwalk virus) are the most common cause of diarrhea in the United States. The most common ones in children are rotavirus and in adults are norovirus. Escherichia coli, Clostridium difficile, and Campylobacter, Salmonella, and Shigella spp. are common bacterial causes.
Numerous bacteria, viruses, and parasites cause diseases in the intestines that result in diarrhea, dysentery, constipation or perianal irritation. They may also cause nausea, vomiting, and abdominal cramping. If the infection is in the small intestine, symptoms include watery diarrhea and vomiting. Infections in the large intestine can cause diarrhea and can result in an invasive and inflammatory disease called dysentery (small fecal volume with mucus and blood) (Table SI-1). Table SI-1.