Hello, moms. It's been a while since I was last here. Please advise me...

Hello, moms. It's been a while since I was last here. Please advise me on this matter. My son currently eats everything except for sour milk products (which he doesn't accept at all), and he goes to a nanny who feeds him regular food, just like we were all fed. But.. lately, he's been having more frequent constipation. He goes normally a couple of times, and the third time he's constipated. We can't do without an enema, as the stool forms with a diameter almost like that of adults. I don't know what to do. He drinks water well throughout the day, unfortunately, he doesn't eat prunes either. Are there any remedies or products that help start and normalize the intestinal function of children at such an age? Please advise 🙏🏻 Thank you in advance for your response.