Age of onset. Parent expectation of stool pattern. Stool consistency, size, frequency, soiling, abdominal pain, anorexia, tenesmus. Infants should pass meconium in first 24 hours. Palpable abdominal mass.
Rectal exam reveals hard stool present with dilated ampulla.
Anal fissure may be present. Abdominal flat plate will show stool filling the colon. Barium enema to demonstrate atresia. Rectal biopsy for Hirschsprung's. Thyroid functions and electrolytes and calcium as indicated.