It is a good carbonated drink. It was originally made for the athelets and now used as a snack beverage. But I suggest you to consult with your doctor before give a one year old baby this drink. I don't know about the condition of your baby. The doctor can tell specifically after examination.
Children can take 7up as it is good for their digestive system..ORS is very essential as diarrhea decreases the level of water and minerals in body...and deficiency of it is very dangerous...
Yes they should it helps them feel better if it doesn't then there are these drinks at Wal Mart that cure Diarrhea.
They can drink gatorade but pedialite works the best, although I've you don't have gatorade or pedialite just get the person to drink plenty of fluids