Some common causes of white foam in your poop are infections such as pancreatitis, and irritable bowel syndrome as well as gastrointestinal disease as well as other viral and bacterial infections.
If the white foam in your poop doesn't clear up within a few days you should see a doctor about it.
White foam in poop is never normal though so always get it checked out because it could lead to something more serious.
Usually though it's just an infection that will eventually clear up or could be you suddenly have irritable bowel syndrome.
Those conditions are not dangerous but a doctors visit would still be a good idea to make sure your health is in good condition.
I once had white foam in my poop and it turned out to just be a temporary bacterial infection that cleared up with antibiotics.