Some babies cry before passing stools or while passing stools normally and after passing they stop crying.it is normal.
But if baby keeps on crying persistently or passing hard stools, or passing streaks of blood in stools, ( anal fissure) try to evaluate at nearest pediatrician. Is the baby top fed or breast fed ? Is the baby on some supplements?
consulting nearest family pediatrician is best...
Next Steps
Try to know the cause and get treated
Health Tips
Don't take herbal medicine or gripe water or woodwards etc....they won't help. consult ur doctor