Who had problems with poop? We're on it! I found red streaks in my sto…

Who had problems with poop? We're on it! I found red streaks in my stool, I went to the pediatrician, she asked what you eat? I say I follow a diet, and she said then nothing is wrong ?It happened twice for us, with a week-long interval approximately! Who has described it in detail, please tell me what the doctors told you? ????