Mom, I'm going crazy, the child is eating bananas for the first time, he…

Mom, I'm going crazy, the child is eating bananas for the first time, he went to the toilet and saw black fibers, I was scared that it was worms, he went again and they stayed, but not black anymore, I know what happens from bananas, when you press them they spread out, I'm going to the hospital, but not today, it's too late, what do you think this is?