Common causes for childhood constipation are dietary, developmental, behavioral, hormonal disturbances and surgical causes.
Dietary reasons predominate among all these causes. Foods which are low in roughage (fiber) or residue (indigestible portion which is passed out as feces) lead to smaller volume of stools and can be constipating in nature. Classical example is a child who is sustained on a primarily milk-based diet even after first 6 months of age. These kids may take even 1 litre of milk per day but are constipated as milk has hardly any fibre to form stools. Plus, these children have anemia as milk has negligible iron content. Diets in which majority of foods consist of junk foods made from refined flour such as chocolates, chips, burgers, pizza, biscuits etc have a low fibre content but are rich in fats and calories. They are nutritionally imbalanced and lead to obesity and constipation.
Children start to sense impending stools and urine by 6 months and learn to control urine earlier than stools. It is imperative to start training the child properly at 1 – 2 years of age and slowly; aggressive training can lead to fear in child’s mind and stool retentive behavior. Kids with disturbed family atmosphere and those with recent family losses tend to respond to the stress by constipation.
Various small incidents can set the trigger for constipation in small children. A day or two of illness, travel or sudden dietary change may cause hard stools and pain while passing them. A bad diaper rash can also cause painful passage of stool. School kids may hold the stools out of embarrassment, fear or any other stress factor. If this continues, it may lead to constipation. Preschool and school kids should be encouraged to go to toilet regularly even if they say that they don’t feel the urge. A glass of warm milk may help in starting a bowel movement.
Among surgical causes responsible for constipation are Hirschsprung’s disease- a disorder of intestinal nervous system whereby the outlet muscles cannot relax, leading to constipation and variant of malformations of anus called anorectal malformations. These are easily correctable if the correct diagnosis is made in early childhood.
Hypothyroidism or deficiency of thyroid hormones is a common and underdiagnosed cause of childhood constipation. Classical signs of hypothyroidism seen in adults like puffiness, weight gain, hair loss may not be obvious in children. Hypothyroidism is easily correctable by giving hormonal replacement therapy.
After all these causes have been excluded, there remains a large group for which no cause can be ascertained – so called Idiopathic constipation. Some of these cases have family history of constipation, other have slow movements of intestine called slow colon motility. It is not proper to label the child as having idiopathic constipation until all the other causes have been thoroughly ruled out by careful and detailed history and clinical examination ably supported by investigations.
Stool that is held back gradually fills up the rectum and colon and stretches it out of its normal tubular shape. Gradually water is absorbed, and the stools become hard; longer it is held back, harder it becomes. In the normal circumstances, nerves sense the stools in colon and send a message to push out the stools; for this to happen the outlet muscles need to relax at the same time. In severely constipated children, the colon muscles don’t contract, and outlet muscles don’t relax. Hard stools irritate the intestine and liquid stools may be passed around confusing the situation. This is called paradoxical diarrhea; paradoxical as constipation is the primary problem. These small amounts of stools may be passed involuntarily (without control) by the child earning wrath of the parents which worsens the constipation.
Stretched colon also becomes less sensitive to stool being there, the child may no longer sense that he needs to pass stools. Coupled with anticipation of pain, he sets off the vicious cycle of stool retention.
Management of dietary constipation in childhood involves cutting down on milk intake, including foods with high residue& fibre (salads, whole flour, pulses, fruits), ensuring adequate water intake and regularizing stooling habits. Initially when the milk intake is cut down, the child may not accept other foods well and remain hungry, but it is important at this point not to encourage milk again. Slowly within a week or ten days the kids start accepting other foods.
For idiopathic constipation first and foremost is behavioral therapy and dietary changes. Behavioral therapy involves regular stooling by alarm clock and encouragement. Dietary modifications can be done by using Fitterfly Mobile App and Nutritionist consultation by a Pediatric Dietitian at Fitterfly. (www.fitterfly.com )
Mild laxatives like milk of magnesia, lactulose, liquid paraffin may also help in this situation. Bulk stools softeners like Fibril (isabgol derivative) or isabgol itself may increase the stool volume and make it soft. If the child is loaded with hard stools it may be helpful to clean out the rectum with enemas for some days, so that the rectal sensation returns. If these are not effective, then newer therapies like botulinum toxin injections can be tried in selected cases. It is effective in those patients who have non-relaxing outlet muscles; botulinum toxin reversibly paralyses these muscles so that the child can not voluntarily control the stools. The fear of passing hard stools is taken care of and the vicious cycle is broken. For the children who have developed sores due to passage of hard stools (called fissures), application of Glyceryl Trinitrate therapy or botulinum toxin injections are very effective.
It is important that the constipated children are given scientific and individualized treatment and not a blind blanket therapy. For this a multispecialty clinic including a Pediatric surgeon or urologist, Pediatrician, trained nurses and a child psychologist would be an ideal setup. Then only can these children be ensured of effective treatment regimen and a prospect of normal growth and development.