Symptoms that may be present in newborns and infants include:

• Difficulty with bowel movements
• Failure to pass meconium shortly after birth
• Failure to pass a first stool within 24 - 48 hours after birth
• Infrequent but explosive stools
• Jaundice
• Poor feeding
• Poor weight gain
• Vomiting
• Watery diarrhea (in the newborn)

Symptoms in older children:

• Constipation that gradually gets worse
• Fecal impaction
• Malnutrition
• Slow growth
• Swollen belly

Milder cases may not be diagnosed until a later age.

During a physical examination, the doctor may be able to feel loops of bowel in the swollen belly. A rectal examination may reveal a loss of muscle tone in the rectal muscles.

Tests used to help diagnose Hirschsprung's disease may include:

• Abdominal x-ray
• Anal manometry (a balloon is inflated in the rectum to measure pressure in the area)
• Barium enema
• Rectal biopsy