A 4-year-old boy presenting with chronic constipation and ribbon like stool

Dr. Md. Benzamin (Resident): A 4-year-old boy presenting with constipation for 1 month of his age. He used to defecate 3-4 days interval with rectal stimulation. The stool was semisolid, ribbon-like, and not associated with abdominal or perianal pain. He had a history of delayed passage of meconium. There was no history of the delayed developmental milestones. He received several medications including lactulose, magnesium hydroxide but there was a poor response.


Provisional Diagnosis
Hirschsprung's disease

Differential Diagnosis
Dr. Kaniz Fathema (Resident): As the child was well thriving with no facial dysmorphism, and no features suggestive of hypothyroidism, spinal cord defect or neurological disease, we differentially thought about functional constipation.

Functional constipation
Dr. Fathema: Constipation is a common chronic disorder of the pediatric age group, affecting 1% to 30% of children worldwide. 1 In Asia, the prevalence is between 0.5% to 29.6%. 2 Constipation accounts for 3% of all primary pediatric care visits and 10-25% of pediatric gastroenterologist visit. 3 North American Society for Pediatric Gastroenterology, Hepatology and Nutrition defines constipation as a delay or difficulty in defecation, present for 2 or more weeks and sufficient to cause significant distress to the patient. 4 Functional constipation is defined as constipation without objective evidence of a pathologic condition. 5 As per ROME IV criteria for ≥4 years children, the functional constipation is defined as the presence of at least two of the followings present at least once per week for at least one month: a) Two or fewer defecations in the toilet per week in a child of a developmental age of at least 4 years; b) At least one episode of fecal incontinence per week; c) History of retentive posturing or excessive volitional stool retention; d) History of painful or hard bowel movements; e) Presence of a large fecal mass in the rectum; and f) History of large-diameter stools that may obstruct the toilet.
These symptoms cannot be fully explained by another medical condition and symptoms are insufficient to fulfill the diagnostic criteria of irritable bowel syndrome. 6 Functional constipation usually initiates with a painful bowel movement which leads to voluntary withholding of stools to avoid painful defecation. These events lead to large, hard stool, and passage of such stool causes further pain and the child becomes frightens, then avoids defecation by all means. Thus, a vicious cycle develops 7, 8 Presence of following "red flag" exclude the diagnosis of functional constipation, like the passage of meconium >48 hours in a term newborn, constipation starting in the first month of life, family history of Hirschsprung's disease, ribbon-like stool, blood in stools in absence of anal fissure, failure to thrive, bilious vomiting, severe abdominal distention, abnormal thyroid gland, abnormal position of anus, absent anal or cremasteric reflex, decrease lower limb strength/tone/reflex, sacral dimple, tufts of hair on spine, gluteal cleft deviation, anal scar, etc. 9 Dr. Benzamin: As the patient having red flag signs that are delayed passage of meconium, constipation straining in the first month of life, and have a poor response to treatment of functional constipation, we have a strong suspicion about Hirschsprung's disease. So, we did barium enema which showed a dilated colon and a significant amount of contrast retained in post evacuation and 24 hours film ( Figure 1). So, we went for a rectal biopsy.

Dr. Hazera Akther (Resident):
The rectal biopsy should be done for confirmation of Hirschsprung's disease, if initial tests suggest the diagnosis of Hirschsprung's disease, or have a high index of suspicion. The gold standard for the diagnosis of Hirschsprung's disease is a full-thickness biopsy.
Several samples of the rectal mucosa should be obtained 1 to 3 cm above the dentate line and should include the submucosa. The rectal suction biopsy collects only the mucosa. The diagnostic pathological findings are the absence of submucosal and myenteric ganglion cells with hypertrophied nerve trunk. The sensitivity and specificity of rectal suction biopsy are 96.8 and 99.4 respectively. If no hypertrophic nerve trunks are found, then a fullthickness biopsy maybe indicated. [10][11][12] Dr. Bishnu Pada Dey (Assistant Professor): Histopathology report of the rectal biopsy showed disorganized, non-myelinated, nerve bundles present in myenteric plexus and Meissner's plexus.
No ganglionic cell was seen in the myenteric plexus and Meissner's plexus ( Figure 2). These features are suggestive of Hirschsprung's disease.
The histopathology of Hirschsprung's disease includes the complete absence of ganglia in both Meissner submucosal plexus and Auerbach myenteric plexus. Associated nerve hypertrophy is a helpful clue but is not diagnostic. Ganglia in the newborn are smaller than in the older child and nucleoli and Nissl substance may be absent. Ganglia near the junction of the ganglionic and aganglionic segment may be decreased in number or be small with abnormal staining patterns. 13

Hirschsprung's disease
Prof. Mohammad Tosaddeque Hossain Siddiqui: Singlestage transanal pull-through operation was done with resection of aganglionic segment and anastomosis of normal ganglionated bowel to the rectum without injuring the anal sphincter and there were no post-operative events. The tissue from the proximal and distal length was examined for histopathological confirmation.  On examination, the abdomen may be distended, failure to thrive and associated congenital anomaly may found. 26  Dr. Sharmista Ghosal (Resident): What is the prognosis?
Dr. Fathema: Hirschsprung's disease is a surgically correctable condition. If the patient appropriately treated, growth and development are mostly within the normal population parameters and intellectual function approximates normal. 41 This patient's post-operative period was uneventful and he was passing stool normally.

Follow-up
The patient was doing well with regular bowel movement on 2 weeks after follow-up.

Final Diagnosis
Hirschsprung's disease