Final answer:
Congenital aganglionic megacolon, or Hirschsprung's disease, is characterized by a lack of ganglion cells in parts of the colon resulting in functional obstruction. The primary symptom is constipation, not frequent urination. The most accurate statement is that it is a condition characterized by an absence of ganglion cells in the colon.
Step-by-step explanation:
Congenital aganglionic megacolon, also known as Hirschsprung's disease, is a condition characterized by a lack of ganglion cells in parts of the colon. This absence of ganglion cells leads to a loss of normal peristalsis in the affected segments, resulting in functional obstruction. The primary symptom of this condition is constipation rather than frequent urination, making option b) incorrect. Treatment for congenital aganglionic megacolon typically involves surgical removal of the affected part of the colon, not the gallbladder, making option c) incorrect as well. Diarrhea is not commonly associated with congenital aganglionic megacolon, but rather constipation, making option d) incorrect. Therefore, the most accurate statement is a) It is a condition characterized by an excess of ganglion cells in the colon.