Final answer:
The test of choice for Hirschsprung's (aganglionic megacolon) is rectal suction biopsy, which involves removing a small piece of tissue from the lower part of the rectum and examining it under a microscope. Other tests that may be used to support the diagnosis include a barium enema and anorectal manometry.
Step-by-step explanation:
The test of choice for Hirschsprung's (aganglionic megacolon) is rectal suction biopsy. This procedure involves removing a small piece of tissue from the lower part of the rectum and examining it under a microscope to look for the absence of nerve cells, which is characteristic of Hirschsprung's disease.
Other tests that may be used to support the diagnosis include:
- Barium enema: This test involves filling the colon with a contrast material and taking X-rays to visualize any abnormalities in the colon.
- Anorectal manometry: This test measures the pressure and sensation in the rectum and anus to assess the function of the muscles involved in bowel movements.