Consecutive children with constipation, who presented to the Pediatric Gastroenterology services at Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India between January 2001 and December 2006, were included in this study. Their complete case records were reviewed in detail for an evaluation of their presenting complaints, associated symptoms, age at presentation, duration of constipation, and an analysis was done of their full clinical and etiological profile.

Constipation was defined as a delay or difficulty in defecation sufficient to cause significant distress(1). Patients were considered having functional or idiopathic constipation (FC) if there was no objective evidence of a pathologic condition. Fecal impaction was defined as a hard mass in the lower abdomen identified during physical examination, a dilated rectum filled with a large amount of stool found during rectal examination, or excessive stool in the colon identified by abdominal radiography. Digital rectal examination was done in all children on the first visit. Functional fecal incontinence was defined as the involuntary loss of any amount of feces once a week or more after attainment of toilet skills. Secondary or organic causes of constipation were assessed in appropriate clinical settings with appropriate investigations. A confirmatory diagnosis of Hirschsprung’s disease (HD) was made only after rectal /colonic biopsy showed the absence of ganglion cells. Spinal abnormalities in suspected cases were confirmed with magnetic resonance imaging (MRI) of the spine. Barium enema, anorectal manometry and rectal biopsy were done only in suspected cases of Hirschsprung disease.

Children with FC were treated with a well-defined treatment plan intended to clear fecal retention, prevent future retention, and promote regular bowel habits. Polyethylene glycol (PEG) was used for disimpaction at a dose of 20ml/kg/hour (reconstituted solution of PEG) for 4 hours and repeated on successive days (up to 3 days), if required. Children younger than 5 years, who were unlikely to drink a large volume, were admitted for nasogastric infusion of PEG at a dose of 25 mL/kg/hour (maximum 1000 mL/hour) till disimpaction was complete. Successful disimpaction was defined as passage of clear fluid of nearly same colour and consistency as being used for disimpaction (PEG fluid) per rectum and it was reconfirmed with a digital rectal examination in those who required rescue disimpaction. After disimpaction, patients were started on long-term lactulose (dose 1-2 mL/kg/day) to achieve daily defecation. The dose of lactulose was adjusted to achieve the goal of one to two soft stools per day without any discomfort. Parents were also given information about toilet training and high fibre diet. Parents were educated about the normal defecation process, the importance of dietary fibre and approach to toilet training by making their child to have several defecation trials daily, especially after each meal. After the child had achieved regular bowel habits on a particular dose of laxatives, he was maintained on that dose for 3 to 6 months and then gradually tapered off.

After the initial evaluation patients were followed up after one month and then every 3-monthly. On follow up, laxative dose was adjusted as per response and rescue disimpaction was done if there was a recurrence of fecal impaction.

The clinical outcome was assessed only after 3 months of laxative therapy. Those who had a lesser duration of laxative therapy were excluded from the study. ‘Successful outcome’ was defined as a period of at least 4 weeks with 3 or more bowel movements per week, without pain during defecation and 2 or fewer soiling episodes per month with complete resolution of all associated symptoms as retentive posturing, pain abdomen, and bleeding per rectum(13).

Statistical analysis: SPSS statistical package (version 13. Chicago, IL, USA) was used. Results were expressed as mean with standard deviation or median with range, as required. Categorical data were tested with Fisher’s exact test and continuous data with independent sample t-test. P <0.05 was considered significant.

During the study period, a total of 137 children with constipation were managed. Their mean (SD) age was 59.2 (42.1) months (range, 8 months to 14 years) and 90 of them were boys. The etiological spectrum of constipation is shown in Table I. The majority, 117 (85%), had functional constipation (FC) while the remaining 20 (15%) had an associated organic disorder. Hirschsprung disease accounted for 6% of all cases of constipation and 40% of organic cases (Table II). All patients with HD had history of delayed passage of meconium. Delayed passage of meconium, and presence of abdominal distension were significantly more common in organic group while fecal impaction was more common in the functional group.

TABLE I



Etiology of Constipation in the Study subjects (n=137)

One of the two children with celiac disease who presented with constipation had even undergone rectal biopsy elsewhere to rule out HD. The child with visceral myopathy had two laparotomies (elsewhere) for suspected intestinal obstruction. Laparotomy revealed numerous diverticulae. A full-thickness ileal biopsy, taken during laparotomy, showed features of visceral myopathy and antroduodenal manometry showed no spontaneous MMC (migratory motor complex) up to three hours and small amplitude MMC after octreotide. His lactulose hydrogen breath test was suggestive of small bowel bacterial overgrowth.

Half of the children with functional constipation had their onset of symptoms by 18 months of age. There were only 2 patients under 12 months of age in the functional group (both at 11 months of age). Clinical parameters were compared between children who presented by 5 years of age (n=77) and those who presented later (n=40). Children <5 years of age had a significantly shorter mean duration of symptoms (15.9 ± 11.4 vs 43.9 ± 40.8 months, P<0.001) and more commonly displayed with-holding behaviour (35.1% vs 12.5%, P<0.01) while pain abdomen was significantly more common in children who presented to us after 5 years (10.4% vs 35.0%, P<0.01). More than 84% of children having withholding behavior were either 5 years or below in age. There was no significant difference between these two groups in respect to delayed passage of meconium, mean bowel action/week, straining, painful defecation, fecal incontinence, rectal bleeding, fecal impaction and abdominal distension. Twenty-nine patients (24.8%) had history of bleeding per-rectum, 6 had documented fissure, 2 had unrelated pathology (rectal polyp), whereas rest 21 did not have any active lesion.

On comparing patients with and without fecal incontinence (in the functional group), it was seen that fecal incontinence was more commonly seen in boys than in girls but the difference was not statistically significant. All other variables (as in table II) were comparable between the two groups, except the mean frequency of bowel movement, which was significantly less in the patients with fecal incontinence (2.1 ± 1.3 vs 3.3 ± 1.9, P<0.01). Pain abdomen as a symptom was more common in girls (29.3%) than in boys (13.2%) (P < 0.05) and while painful defecation was also more common in girls, it did not reach a level of significance.

Of the initial 117 patients with FC, 24 were lost to follow-up and another 17 had incomplete follow-up of less than 3 months. Thus response to therapy could be assessed in only 76 patients who had a mean follow-up duration of 15.0 ± 16.7 months. Overall, ‘successful outcome’ was obtained in 72/76 (95%). Only 4 patients failed to achieve this outcome on laxatives, including one who did not show good response to second disimpaction and later got lost to follow-up. Fourteen (18.4%) patients had recurrence of symptoms on follow up and 8 (10.5%) of them required rescue disimpaction after a median duration of 5.5 months (range 1.5-17 months) of the first disimpaction. As a maintenance therapy, lactulose was changed to PEG in 14 children, 11 due to recurrence of symptoms while on lactulose and 3 due to side effects of lactulose (bloating and abdominal distension). It is also noteworthy that seven of the eight patients (87.5%) who needed rescue disimpaction had history of fecal incontinence in comparison to 21 of 68 patients (31.0%) not needing rescue disimpaction, the difference being significant (P <0.003).

Hirschsprung’s disease, the most important organic cause of constipation is reported in 3% of constipated children referred to the gastro-enterologist(18) and it accounted for 6% of the constipated children presenting to us. The possibility of HD should be considered when there is a history of delayed passage of meconium, poor growth, significant abdominal distension, and an empty rectal vault in spite of palpable abdominal fecal matter(1,7,19,20). All 8 children with Hirsch-sprung’s disease in our study had significant abdominal distension and had a history of delayed passage of meconium. None had rectal fecal impaction, or withholding behaviour or fecal incontinence, which are hallmarks of functional constipation(20).

Two children in our study had celiac disease and presented with constipation rather than diarrhea. This association of celiac disease and constipation has also been reported previously(21,22). It is imperative to suspect celiac disease in any case of constipation who has failure to thrive, anemia, alternating diarrhea and constipation, or have abdominal distension with bloating and flatulence along with constipation(1,2).

One of the commonly seen clinical characteristic in functional constipation is withholding behaviour and is reported in 50-60% cases of functional constipation (1,3,13-16,20). Only 27% of our patients exhibited this type of retentive posturing similar to 31.2% reported in a similar retrospective study(12). This low frequency in our study could be due to poor data retrieval or retrospective design or it could be due to misinterpretation of symptoms. As symptoms being noted verbatim, if the parents were not able to differentiate between the concept of retentive posturing and what they perceived as straining (reported in 35% of our cases but not reported by others), it is likely that many cases with withholding maneuvers have been misinterpreted by the parents as attempts at straining for defecation(1,13).

Many children with FC have associated fecal incontinence and the prevalence ranges from 18-89%, but on an average it is 40%-60% (12-14, 16). In our study, 31% of children had associated history of fecal incontinence. The mean frequency of bowel movement was significantly less in the patients with fecal incontinence than in those without fecal incontinence. Most of the patients who needed rescue disimpaction on follow up had history of fecal incontinence, pointing to the fact that children with fecal incontinence are a subset of constipation with more severe symptoms and may need rescue disimpaction on follow-up(11). Others have also found fecal incontinence to be a negative prognostic factor for a successful outcome of therapy(9,23). All our patients were started on the treatment programme as outlined above and ‘successful outcome’ was obtained in the majority of cases, with meagre 5% not responding adequately to laxatives mainly due to non-compliance to dose and non-cooperation with toilet training. Similar response rates have been previously documen-ted(13). It is important to note that mere laxative therapy does not guarantee cure in functional constipation. Dietary advice (reduction of milk intake and increase in high fibre containing solid food intake) and toilet training play an important role in the successful outcome of medical therapy. With regular follow up we ensured compliance to high fibre diet and regular toilet training and that is responsible for the good response noted by us.

A subset of patients with constipation may be refractory to usual medical therapy of laxative, diet and toilet training and one of the reasons is motility disorder. As per the motility pattern three main types of functional constipation have been described; normal colonic transit constipation, slow transit constipation and functional outlet obstruction(24). The prokinetic drugs like tegaserod (not yet approved for use in children) is useful in slow transit constipation and biofeedback helps in functional outlet obstruction cases.

In view of retrospective nature of our study the main limitation is that almost 35% of children with functional constipation either were lost to follow up or had incomplete information. Hence, the efficacy of therapy could not be assessed properly.

To summarize, functional constipation is the most common form of constipation presenting in children in India as in the West, though upto 15% of patients may have an organic cause in whom history of delayed passage of meconium, presence of abdominal distension, and absence of fecal impaction in rectum point to an organic pathology. Patients with fecal incontinence along with constipation are a subset with more severe disease. We hope this study will increase the awareness about functional constipation in India and pediatricians/pediatric surgeons will stop investigating all cases of constipation for Hirschsprung disease.

Contributors: VK: Data collection, analysis and drafting the manuscript; UP: Protocol development, data collection and writing the manuscript; SKY: Data collection, analysis and manuscript preparation.

Funding: None.

Competing interests: None stated.

2. Benninga M, Candy DC, Catto-Smith AG, Clayden G, Loening-Baucke V, Di Lorenzo C, et al. The Paris Consensus on Childhood Constipation Terminology (PACCT) Group. J Pediatr Gastroenterol Nutr 2005; 40: 273-275.

3. Rasquin A, Di Lorenzo C, Forbes D, Guiraldes E, Hyams JS, Staiano A. Childhood functional gastrointestinal disorders: child/adolescent. Gastroenterology 2006; 130: 1527-1537.