Doctor's Notes on Constipation in Children
Constipation in children means the infrequent passage of stools or the passage of hard stools in the pediatric population. Signs and symptoms of constipation in children, which is common, usually includes bowel movement frequency, stool consistency and pain; in general, three bowel movements per week with the stools being hard and/or painful to pass indicate constipation. Other signs and symptoms include complaints of vague to severe abdominal pain around the navel, decreased appetite, nausea and/or vomiting, urinary incontinence and/or bedwetting and recurrent urinary tract infections. Infants having hard stools may extend their legs and squeeze their anal and buttock muscles to prevent stool passage; toddlers may stand up on their toes, rock back and forth and hold the legs and buttocks stiffly.
Cause of constipation in children can be medications such as coal medications, antacids, antidepressants, anticonvulsants, chemotherapy, and pain medication that includes narcotics. Medical disorders that can cause chronic constipation in children include hypothyroidism, a congenital condition like Hirschsprung’s disease (lack of nerve cells), diabetes, abnormal electrolyte levels, lead poisoning, cystic fibrosis, spinal cord problems and mental retardation.
The majority of children with constipation have it intermittently and do not have a medical disease or disorder.
Constipation: Foods to Eat, Foods to Avoid Quiz

You are constipated if you don't have a bowel movement every day.
See AnswerREFERENCE:
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.