Dental Veneers are cosmetic dental prosthetics that are meant to cover the teeth. It is not exactly a prosthetic, in the sense that it replaces something that was lost (as in the case of dentures, dental bridges and dental implants.).
According to Wrong Diagnosis, one of the causes of mucus stools in children is bacterial overgrowth. Normally there is a certain amount of bacteria in the digestive tract. This is healthy and assists in digestion. But if it grows out of control, then it can contribute to mucus in the stool.
Other conditions that can cause larger amounts of visible mucus in the stool include bacterial infections, anal fissures, a bowel obstruction, or Crohn's disease (the second main form of IBD). If stool is also bloody and there is pain, that's a reason to get in touch with a doctor right away.