Cracks in Toilet Bowl Serious?
Worry.
There's no reason for &quot;cosmetic surface cracking&quot; 20 years on that doesn't come with sub-surface structural issues. Something is not right in there, and it will come apart one of these days - tomorrow or 5 years on, we don't know, but it's likely to be inconvenient, messy, and quite possibly involving an embarrassing trip to the emergency room for cuts sustained in the failure.