- With constipation, bowel movements are infrequent and stools are hard and difficult to pass.
- Constipation is mainly due to problems in the lower part of the bowel known as the colon.
- The younger the child, the more likely it is that the problem is due to an organic cause.
- It is important to exclude Hirschprung’s disease, where a part of the bowel cannot relax and allow stools to pass through, due to an absent nerve supply to this part of the bowel.
- The commonest cause of infrequent passing of stools in a baby is underfeeding.
- Treatment of constipation is treating the cause.
- A distinction must be made between soiling and encopresis.
- Soiling is the involuntary passage of small amounts of stool due tochronic constipation.
- Encopresis is the passage of normal stools at inappropriate times. This is usually the result of poor toilet training or a severe emotional disorder.
With constipation bowel movements are infrequent and the stools are hard and difficult to pass. The average baby passes three to six stools per day in the newborn period, one to two stools per day at one year and one per day or every other day in the pre-school years. Normal bowel frequency can vary widely and some breastfed infants have a bowel action of normal consistency only once every two, three or four days and older children may be equally infrequent, yet pass normal stools.
What are the harmful effects of constipation? The myth of serious toxic effects caused by unpassed stools has long been discounted and it is based on what the medical profession taught generations ago. The effects are purely local in the lower bowel. Nevertheless, the local effects, minor in their beginnings, may eventually lead to serious problems for some children.
Constipation in infancy
Although the vast majority of children presenting with constipation have no serious underlying pathology, the younger the child, the more likely it is that the problem is due to an organic cause. It is particularly important to exclude Hirschsprung’s disease.
Some organic causes of constipation
- Hirschprung’s disease
- Anorectal anomalies
- Cystic fibrosis
- Metabolic and endocrine: Hypothyroidism, hypercalcaemia, hypokalaemia
- Renal failure
- Toxic: lead poisoning
- Spinal cord lesion
- Cerebral palsy
In this condition a segment of the bowel, usually the recto-sigmoid junction, has no nerve supply, and does not relax to allow the passage of stools. The condition is present at birth. In the early months, diarrhoea or infrequent passage of stools or even complete obstruction may occur. The child may be underweight and have a poor appetite. Abdominal distension is often present. The rectum contains no faeces. Soiling is extremely rare. A Barium enema shows a narrow segment usually in the rectum or sigmoid colon, but occasionally higher up in the intestine. Removal of the abnormal segment by an abdomino-perineal operation gives excellent results.
Notes on causes of constipation in infancy
- The commonest cause of abnormal infrequent defecation in infancy is underfeeding. Underfeeding, whether on breast or bottle, in the first month or two of life, may lead to the passage of small, semi-liquid, dark-green stools.
- Constipation may result from insufficient fluid intake, especially during an illness.
- Constipation may result from a change in feed or routine. Casein-containing milk formulae are more likely to constipate than low-casein varieties.
- Constipation can occur in infants who are well-nourished and who are getting all the food they need. In these infants the process of absorption of water may be unduly active.
- Straining to pass a hard stool may result in a small tear of the anus, known as a fissure of the anus, and the stool may then show a small streak of fresh blood. The pain on defecation results in further retention of the stool. If the fissure is not recognised and treated, it can become chronic. Severe faecal loading in the older child often has its origin in such an incident in infancy.
How is it treated?
The treatment of infrequent defecation in infancy is the treatment of the cause.
- The breastfeeding infant with an infrequent bowel pattern needs no treatment.
- Underfeeding should be rectified.
- In infants under four months on formula feeds, an increase in fluids between feeds is often all that is required.
- Over four months, the introduction of cereal and fibre in the form of sieved vegetables and unsweetened stewed fruits is beneficial.
- A fissure of the anus should be treated by the application of an ointment containing a topical anaesthetic, such as lignocaine, to the anus. This ointment must be inserted gently into the anal canal with the little finger three times a day, if possible, just before a stool is passed.
- A stool softener such as lactulose or sorbitol is also helpful.
- If the stools remain hard and infrequent, then a safe and helpful measure is the use of senna tablets or granules at night for a limited period.
Avoid all preparations containing phenolphthalein, castor oil or cascara. Phenolphthalein and cascara can damage the colon and induce dependency. Castor oil contains ricin, which is carcinogenic. Medicinal paraffin affects absorption of fat-soluble vitamins.
Constipation in older children
The cause of constipation in older children is often difficult to pinpoint and several factors may initially have been involved:
- Loss of appetite during an acute illness
- The prescription of constipating medications for diarrhoea or fever, such as codeine.
- Pain from an anal fissure
- A stressful life event
- Having to rise early and travel long distances to school in the morning
- The need to use a cold and often unhygienic outside toilet, or dirty toilet facilities at school
- Over-rigid management by parents, determined to see their child toilet-trained at an early age
Retained faeces become hard and painful to expel and as they build up, the rectum gradually becomes distended, reducing rectal sensation and thus diminishing the urge to defecate. There is frequently over-flow soiling caused by fluid stool and mucus passing around the hard faeces and staining the child’s underwear.
The child may be smelly and become the butt of jokes at school. This can have profound effects on well-being and self-esteem. Parents or teachers may adopt a punitive approach towards the child and compound an already unfortunate situation.
A special problem is that of chronic constipation in children with mental handicap and neurological disabilities, such as cerebral palsy or spinal cord abnormalities.
Chronic constipation should be suspected when abdominal and rectal examinations show palpable faeces, confirmed by abdominal X-rays showing faecal content that may fill the entire colon. Gross distension of the bowel is not commonly seen.
Children with chronic faecal loading are often misdiagnosed as having chronic diarrhoea, non-specific abdominal pain or psychological encopresis. It has also been shown that constipation can cause reversible urinary tract abnormalities that may result in urinary tract infection and incontinence.
How is it treated?
Clearing the bowel:
- The colon and rectum must be evacuated using repeated Microlax® (5ml) or Fleet® (62ml) enemas.
- In advanced cases the administration by mouth of large volumes of a balanced electrolyte polyethylene glycol solution such as Golytely® is helpful.
- The diet should be carefully adjusted to include more fibre such as in bran-containing cereals, brown or whole-wheat bread, vegetables, and more fruit and fluid intake.
- In addition, bulk laxatives should be given, for example Metamucil® (psyllium), or Fibogel® (ispaghula) and continued for several months.
- If this form of laxative is insufficient, it should be complemented with a stool softener (lactulose) or bowel stimulant (senna tablets or granules, one to three tablets or teaspoons at night for three to six weeks).
- Encouraging a regular bowel habit:
A child should be encouraged to use the toilet at a fixed time every day and rewarded for doing so (behaviour modification). Punitive measures and harsh discipline are often at the root of the problem and parents need to be advised about this.
Faecal soiling and encopresis
As distinct from the faecal soiling or overflow incontinence in chronically constipated children just described, encopresis is the passage of stools at inappropriate occasions. Encopresis generally results from inadequate training or severe emotional disorder.
Some children will have had continuous encopresis from infancy. This sometimes results from poor toilet training in early childhood. Children with encopresis respond well to a proper training programme, warmth and encouragement.
Underlying emotional disturbance
Encopresis can reflect a poor parent-child relationship, often of long standing, and may be associated with other psychiatric problems. This symptom nearly always indicates that the child and parents need expert psychological assessment and help without delay. This will include behavioural (star chart) and individual psychotherapy, and parental counselling and family therapy to modify attitudes and family interactions.
Lastly, it should be borne in mind that faecal soiling may occasionally be a manifestation of sexual abuse.
Laxatives for use in children
Bran and other vegetable fibres are best
Metamucil® (psyllium), ½ to 1 sachet daily
Fybogel® (ispaghula), ½ to 1 sachet daily
Senokot® (senna), 1 to 3 tabs at night
Osmotically active laxatives
Magnesium hydroxide, 2.5 to 5.0 ml daily (suitable for young infants)
Duphalac® (lactulose), 2.5 to 15 ml daily
Golyteley® (balanced electrolyte polyethylene glycol solution), 1 sachet in 1 litre of water: 20-25 ml/kg/hour
Avoid all preparations containing phenolphthalein, castor oil or cascara.
Written by Prof M. A. Kibel, University of Cape Town
Reviewed by Prof Eugene Weinberg, Consultant Paediatrician, UCT Lung Institute, April 2011