Sentence:  Normal stooling is widely variant. Some infants only have one <WSD>stool</WSD> per day, especially those on formula feeding. Others may stool with each feeding. Such frequent stooling is common in breast-fed infants during the first month of life. 
Meaning of the word marked with <WSD> tags:  A production of feces or excrement, an act of defecation, stooling.