Is this normal for a new born?

My baby is one week old and I don’t know if this is normal or not but for the first time he has been pooping for the past hour 6 poopy diapers and I don’t know why. Nothing about my diet has changed and the only thing that changed for him is the formula that I used, I went from the regular Enfamil to the Gentlaese enfamil. Would giving him water cause him to have a upset stomach? I asked because every time he has a hiccup my mother wants to give him water even though I told her the doctor said nothing but breast milk and formula and yesterday he was watching him while I was at the hospital.