Final answer:
Congenital megacolon is another name for Hirschsprung's disease, a common cause of lower GI obstruction in neonates characterized by the absence of ganglion cells in the distal colon. It prevents normal passing of meconium after birth and can lead to serious complications if not treated.
Step-by-step explanation:
Another name for Hirschsprung's disease, which is the most common cause of lower gastrointestinal (GI) obstruction in neonates, is congenital megacolon. This congenital condition is due to the absence of ganglion cells in the distal colon, resulting in a lack of peristalsis in that segment and causing a blockage. The impacted section remains contracted and the normal section proximal to the defect becomes distended with stool and gas.
During normal fetal development, meconium accumulates in the intestines, and it is usually passed after birth. However, in Hirschsprung's disease, this may not occur normally, causing a bowel obstruction. Infants typically present with symptoms like failure to pass meconium within the first 48 hours after birth, abdominal distention, and vomiting.
Mechanisms of fetal distress such as maternal drug abuse, hypertension, or a defect in the placenta can all cause the premature passage of meconium which can be a sign of distress. If not diagnosed and treated, Hirschsprung's disease can lead to serious complications such as enterocolitis or potentially fatal bowel perforation.