Final answer:
The assessment finding unassociated with imperforate anus is the passage of currant jelly-like stool, which is indicative of intussusception rather than imperforate anus.
Step-by-step explanation:
The assessment finding that is unassociated with the diagnosis of imperforate anus is the passage of currant jelly–like stool. Imperforate anus is a congenital defect where the opening to the anus is missing or blocked. The symptoms typically associated with this condition include the failure to pass meconium within the first 24 hours after birth, stool in the urine due to an abnormal connection between the rectum and the urinary tract (fistula), and difficulty inserting a rectal thermometer due to the blockage. However, the passage of currant jelly–like stools is more characteristic of intussusception, a condition where part of the intestine slides into an adjacent part of the intestine, not imperforate anus.