I think it is pretty clear from the very beginning of the story that Ender, through the course of this excellent scientific fiction novel, experiences any number of conflicts that seriously threaten him. First of all, a great place to start is considering how the series of external conflicts that he faces are all stage-managed to a certain extent, or observed. Note what the observers who watch him say at the beginning of the second chapter, after Ender has just beaten up the gang leader effectively:
"I went back through some of the tapes. I can't help it. i like the kid. I think we're going to screw him up."
"Of course we are. It's our job. We're the wicked witch. We promise gingerbread, but we eat the little bastards alive."
We cannot escape the disturbing conclusion that Ender is being formed by the violence that these observers either deliberately unleash upon him or sit passively by and watch him suffer. It is only through these experiences that Ender can gain the necessary skills and qualities necessary to save mankind, it is suggested.
Of course, Ender arguably experiences internal conflict as well, coming from the immense pressure he faces when he begins his "education" and starts playing the "Game." Ender's whole life is one massive exercise in conflict, which results in an individual who has been, in the words of the observers, "screwed up" or "eaten alive."