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

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?