This document discusses oral rehydration solutions (ORS) for treating diarrhea and dehydration. It describes different types of ORS, including sodium bicarbonate-based, tri-sodium citrate-based, and reduced osmolarity ORS. The World Health Organization now recommends a single, low osmolar ORS for all ages and types of diarrhea. The key ingredients in ORS - sodium chloride, potassium, trisodium citrate, and glucose - help replace lost electrolytes and fluids. While bicarbonate-based and tri-citrate ORS differ in stability and stool output, the reduced osmolarity ORS lowers risks of vomiting and hypernatremia.