Table 3.
Common anorectal disorders presenting with delay or failure to pass meconium in the neonates
| Diagnosis | Rate | Common physical findings | Suggested investigation: expected findings | Initial management |
| Meconium plug syndrome | 1/500-1000 | Abdominal distension, normal anus and anal sphincter complex | Contrast enema radiologic examination: meconium plug in colon | Rectal stimulation with finger or saline enema |
| Hirschsprung’s disease | 1/4000 | Abdominal distension, tight anal sphincter, empty rectum, sudden evacuation of stool on digital rectal examination if “transitional zone” is reached | Contrast enema radiologic examination without colonic preparation: transitional zone separating aganglionic segment and dilated proximal colon | Intravenous hydration, gastric decompression, rectal washout with warm saline, and consider colostomy in high-grade obstruction and intravenous board-spectrum antibiotics in those with suspected diagnosis of Hirschprung-associated enterocolitis |
| Imperforate anus (IA) | 1/5000 | Absence or stenosis of anus, perineal fistula (low IA), meconium in urine (rectourinary fistula: low or high IA), flat or not well formed median raphe (high IA), cloaca (high IA), VACTERL anomalies1 | Inverted lateral radiography (invertography) or transperineal ultrasonography: differentiation between low IA and high IA | Anal or fistula dilatation for temporary relief of obstruction and plan for elective posterior sagittal anorectoplasty (low IA), loop sigmoid colostomy (high IA or some low IA) |
| - Low IA = distal rectal pouch lining below or at the puborectalis muscle | ||||
| - High IA = distal rectal pouch lining above the puborectalis muscle |
1
VACTERL anomalies include vertebral anomalies (V), anorectal malformations (A), congenital cardiac anomalies (C), tracheoesophageal fistula or esophageal atresia (TE), renal and urinary anomalies (R), limb lesions (L).