Pediatric constipation: Clinical

Constipation in children is a decreased stooling frequency or increased difficulty of passing stool, as compared to a child’s baseline. 

Normally, full-term neonates pass meconium, which is the very first stool which is usually thick and green-black, within the first 48 hours of life. Premature neonates, meaning those born before the start of the 37th week of gestation, can take a bit longer. After that, during the first three months of life, infants have about two to four stools a day. By the age of two years, toddlers generally have one or two stools per day. And by age four, children typically have one bowel movement per day.

If a neonate doesn’t pass meconium within the first 48 hours of life, has abdominal distention, refuses to feed, or has bilious vomiting, it should raise suspicion for imperforate anus, meconium ileus, and Hirschsprung disease. In an imperforate anus there’s a non-patent or tiny anal opening, which is anteriorly displaced relative to the base of the scrotum or vagina. In some cases, there can also be a fistula between the rectum and the urethra, bladder, or vagina, through which some meconium may drain.

About half of the neonates with an imperforate anus also have other congenital anomalies associated with VACTERL syndrome. VACTERL stands for Vertebral defects, Anal atresia, Cardiac anomalies, Tracheoesophageal fistula, Esophageal atresia, Renal anomalies, and Limb anomalies. So, the next step is to perform a posteroanterior and lateral-view x-ray of the sacrum, called a cross-table x-ray. This can help distinguish between a high-type or low-type defect, meaning that the intestine ends high or low in the pelvis and whether it’s associated with other sacral abnormalities. In addition, an ultrasound of the spine, heart, abdomen and limbs are needed to look for vertebral, cardiac, renal and limb abnormalities. Also, an NG tube can be placed and a chest X-ray can be obtained to look for signs of tracheoesophageal fistula and esophageal atresia, like the NG tube coiled in the upper esophageal pouch.