My son ate pieces of our newly renovated precast wall and now he has diarrhoea what should i do?

Hydration is best: It's a good sign he's not vomiting nor stuporous. Of course, you'd've preferred he not snack on the wall. Replace his fluids by giving oral drinks (water best) EQUAL to the # of ounces of BM he produces with each bathroom visit. If he's not crying from belly cramping, headaches, & doesn't have abnormal color in the lips, mouth, nail beds, etc. then, take him to his pediatrician otherwise, ER.

Keep diapers handy!: Luckily, there is nothing toxic in these prefab bed walls, so you don't need to worry about any form of poisoning. He has diarrhea as the substances in these materials attract water, thus causing the diarrhea. Keep child hydrated, make sure child knows eating walls is a no-no, and just wait out the diarrhea. It usually resolves with a week. Stay away from high sugar foods, give proteins .