INTRODUCTION: Constipation is a common paediatric problem. It is estimated that it may affect upto 5% of the school age children. In majority of the cases no organic cause is responsible and attention to the dietary habits, proper hydration and reduction in parental anxiety is all that is required. Importance of constipation at this age is that there are many remediable causes which if untreated could result in severe psychological and physical problems later in life.
The definition of constipation differs with different population and could be quite arbitrary in paediatric population. Many a times it depends upon parents' perception. Of late an attempt has been made to develop a consensus to define constipation. These criteria, the "ROME" CRITERIA include atleast two or more of the following for atleast 3 months. They are,
1) two or fewer bowel movement per week,
2) stool weight less than 35 gms/ day ,
3) straining at stool for more than 25 % of the times,
4) hard or lumpy stool atleast 25 % of the times and
5) sense of incomplete evacuation atleast 25 % of the times.
These criteria help to evaluate constipation objectively ,however there is chance of missing acute type of constipation and chronic constipation could be underestimated because of lack of education and understanding of the criteria.
Once the constipation is diagnosed the paediatrician is faced with finding the underlying cause. In most of the cases this is possible by obtaining a detailed history and thorough physical examination, detailed dietary history supplemented by routinely available tests like stool and urine examination and, when necessary, barium enema. We illustrate a few cases to underline points mentioned above.
Case # 1 : A 5 year old girl was admitted with recurrent abdominal swelling and diarrhoea and faecal incontinence. She was a first born, full term normal delivery with normal mile stones. She had passed meconium after about 2 hrs. Her abdomen was enlarged and rectal examination showed loaded rectum. She was evacuated completely with manual removal of faeces ,enemas and laxatives. Barium enema suggested dilated colon upto anus with no narrowing. Full thickness rectal biopsy was showing presence of ganglia ruling out Hirschsprung's disease. Anorectal manometry ,if available , could have helped here. Thyroid functions were normal. Neurological examination was normal. She was diagnosed to have idiopathic constipation. She was put on high fibre diet, Isabgul, laxatives and regular toilet programme which has resulted in significant improvement. Idiopathic constipation with dilation of colon upto rectum is believed to be due to abnormal colonic motility either because of neuronal or muscular involvement. It may take the form of prolonged colonic transit with constipation or at the other end it may be so severe that it may produce pseudo- obstruction. If sluggish colonic motility is the underlying aetiology, prokinetic drugs like cisapride could be useful in high dose.
Case # 2: A 3 year old male, full term normal delivery, second born, was seen for severe constipation. He had passed meconium 72 hrs. after birth. Detailed physical examination was normal, except grossly enlarged abdomen. Rectal examination showed loaded rectum with gush of air on withdrawal of the finger. Barium enema revealed a 3 cms. long narrowing which on full thickness rectal biopsy showed agangliosis, suggesting Hirschsprung's disease. Incidentally the diagnostic biopsy was enough to give him symptomatic relief. Hirschprung's disease is a frequent finding in cases of stubborn constipation. History of delayed meconium passage may not always be present. Contrarily in pre-term infants delayed passage of meconium may be of no importance. If a long undilated segment is present it may pose no difficulty in diagnosis, however in ultra short segment of Hirschsprung's disease diagnostic difficulty is frequently encountered. Skilled radiologist using anal marker could be of tremendous value here. Anorectal manometry is unfortunately not available easily, otherwise this could help by showing rectosphincteric reflex on balloon distention. Many a times the aganglionic segment extends much higher than the barium enema suggests and this is due to dilatation of the aganglionic colon due to chronic faecal overloading. This poses a great challenge to the operating surgeon. At times Hirschprung's disease could be missed through the childhood and only detected in the adolescent or even adult life !
We find following inquiry useful in clinical differentiation of Hirschprung's from idiopathic constipation
1. Delayed passage of first meconium beyond 24 hours and often requiring some form of intervention, like intubation, rectal examination or enema.
2. Constipation from birth.
3. Associated with gross distension of abdomen.
4. Usually soft stool, but without overflow incontinence.
5. Per-rectal examination shows narrow lower rectum and is often followed by explosive evacuation of gas and soft stool.
Case # 3 : A 7 year old girl was referred for constipation for about 2 years. Birth and developmental history was normal. She had bradycardia of 48/min and dry skin. Hypothyroidism was suspected and confirmed. Replacement with Eltroxin produced gratifying results. Other endocrine diseases associated with constipation are, hyperparathyroidism, and diabetes mellitus. Sometimes acute intermittent porphyria attack is also heralded by severe constipation for days.
Case # 4 : A 2 yr. old boy was seen with constipation. Birth and development history was normal. He was still bottle fed, was not taking any vegetables and was eating a lot of biscuits. Physical examination including rectal examination were normal. Barium enema did not reveal any abnormality. With good dietary regime and initial rectal unloading with enemas, he improved and developed normal daily evacuation.
Case #5 : A 4 yr. old boy was seen for constipation. He had extreme straining during defecation and was passing a narrow strand of stool like paste coming out of a tooth-paste tube. Rectal examination revealed anal stenosis. Rest of the examination was normal. Anal dilatation was curative. He may have required anoplasty if dilatations had failed. We recommend following stepwise approach when evaluating a child with constipation.
We recommend following stepwise approach when evaluating a child with constipation.
Step # 1: Detailed medical history including birth history, type of delivery and any complications associated with it, time when meconium was passed, duration of constipation, associated incontinence and encoporosis. Any associated pain, dysuria or bleeding must be inquired for. Detailed ditetic and drug history must be noted. The posture in which the child passes stool and his behaviour before and during defecation.
Step # 2: Detailed physical examination with special reference to perinium to detect any anatomic abnormality. Neurological examination. Rectal examination on an unprepared colon is a must in all cases of constipation. Abdominal examination for distension , visible loops and palpable feculomas.
Step # 3: Stool and urine examination for any infection. Plain X-ray abdomen for confirmation of constipation especially when there is associated incontinence. Barium enema by a skilled radiologist using anal marker, if cons. Rx fails in a suspected non-Hirsch. case and in all cases of suspected Hirschsprung's.
Step # 4: MRI of the spine if neurological abnormality is found or suspected.
Step # 5 : Full thickness rectal biopsy when Hirschprung's disease is suspected. Anorectal manometry where available. [ Hirsch. is supposed to be confirmed if any of the three out of four ( typical S/S, Ba-enema, Manometry, Biopsy ) are definitely positive. ]
Step # 6: Thyroid functions, blood sugar, serum calcium and urinary porphyrins as indicated.