A doctor can usually diagnose an imperforate anus by performing a physical exam after birth. An X-ray of the abdomen and abdominal ultrasound can help reveal the extent of the abnormalities.

After diagnosing imperforate anus, your baby’s doctor should also test for other abnormalities associated with this condition. Tests used may include:
X-rays of the spine to detect bone abnormalities
spinal ultrasound looking for abnormalities in the vertebral body, or bones of the spine
echocardiogram looking for cardiac anomalies
MRI looking for evidence of esophageal defects such as formation of fistulae with the trachea, or windpipe