Yogurt and constipation

Lynzee • Mommy to Ammarie, born on March 3,2016!
Isit true that yogurt helps with constipation? I have Yoplait here at my house, and I need some relief ASAP! Milk of magnesia isn't doing much of anything, stool softeners aren't helping either. 
All the stores are closed until tomorrow, so I can't go get fiber foods.  Help?