1, abdominal x-ray standing plain film: routine examination can initially determine the severity of the lesion and possible prognosis of the lesion. 2, lower gastrointestinal tract barium imaging: the examination means that may cause radiation damage, and is still widely used clinically, is also one of the most important and accurate examination means imaging can clearly diagnose the scope of the lesion site, intestinal dilation and barium discharge. At the same time, it can help the differential diagnosis. 3, abdominal ultrasonography: ultrasonography has developed rapidly in recent years has partially or even completely replaced the traditional diagnostic function of large auxiliary instruments such as contrast tomography, ultrasonography method is simple equipment requirements low objectivity, harmless to the body, but requires ultrasonographers should have extensive clinical experience and certain professional skills in surgical anatomy. 4, rectal manometry: In foreign countries and Hong Kong and Taiwan, the use of more common manometry content for the internal sphincter relaxation reflex and pressure changes in various parts of the anal canal, the method is safe and simple, but requires large and expensive medical equipment, due to the impact of the operator’s subjective judgment of the results of the objectivity is not strong, there is a certain rate of error, especially in newborns and small infants accuracy is not good. 5, rectal mucosal biopsy and enzymatic examination: clinically used physical examination and radiological examination means still can not accurately determine the cause of the rectal mucosal biopsy and enzymatic examination can be considered the method, accurate and objective diagnosis is reliable but invasive examination method, so in the clinical work is often forced to use the general through the above examination will be able to diagnose whether congenital megacolon.