Diagnosis and management of idiopathic childhood constipation in primary care

1. Diagnosis and management of idiopathic childhood constipation in primary care KHALED ELIAN ,MD RAMALLAH APRIL,29TH 2011

2. Constipation has been defined as “a delay or difficulty in defecation, present for two or more weeks, sufficient to cause significant distress to the patient.”

3. Prevalence of constipation: around 5–30% of children • Exact cause not fully understood, signs and symptoms may not be recognised • Common reason for referral to secondary care • Families may be given conflicting advice • Early identification and effective treatment improves outcomes

4. What is normal ? • The frequency of stools in most children decreases from a mean of four per day in the first week of life to 1.7 per day by the age of 2 years. • Over this interval, stool volume increases more than tenfold while maintaining a consistent water content of approximately 75%. • Intestinal transit time from mouth to rectum increases from 8 hours in the first month of life to 16 hours by 2 years of age to 26 hours by the age 10.

5. How does it work • Normal continence is maintained by the resting tonicity of the internal anal sphincter • It can be enhanced by contraction of the puborectalis muscle, which creates a 90-degree angle of rectum to the anal canal. • When more than 15 cc of stool enters the normal rectum, stretch receptors and nerves in the intramural plexus are activated. • Inhibitory interneurons decrease the resting tone in the involuntary smooth muscle of the internal anal sphincter.

6. How does it works (cont.) • Relaxation of the sphincter allows the stool to reach the external anal sphincter and the urge to defecate is signaled. • If the child relaxes the external anal sphincter, squats to straighten the anorectal canal, and increases intra-abdominal pressure the rectum is evacuated of stool.

7. Why it may not work • If, however, the child tightens the external anal sphincter and the gluteal muscles, the fecal mass is pushed back into the rectal vault and the urge to defecate subsides. • Repetitive denial of evacuation leads to stretching of the rectum and eventually of the lower colon, producing a reduction in muscle tone and retention of stool. • The longer the stool remains in the rectum, the more water is removed, and the harder the stool becomes to the point of impaction.

8. Encopresis • Term first used in 1926 to suggest similarity with ‘enuresis’ for wetting • Inappropriate passage of normal stool • Stool passed in pants or deposited ‘elsewhere’ (where it can be found!) • Normal bowel sensation • Often associated with other behavioural problems

9. Causes of constipation in childhood ‘Holding on’ - often initiated by passage of large / painful stool • delay in passage of normal stool • anal fissure • group ‘A’ hemolytic streptococcal anal infection • toilet phobias / fears • Child sexual abuse

10. Causes of constipation (continued) Functional faecal retention -usually associated with soiling • follows from ‘holding on’ unless managed appropriately • child ‘forgets’ mechanics of normal defaecation • May require long term treatment and follow up

11. Functional faecal retention • Symptoms begin after first year • passage of enormous stools • symptoms of increasing faecal loading - soiling/irritability/abdo pain/anorexia • symptoms resolve on passage of stool • seemingly irrational coping skill behaviour • nonchalant attitude / hiding underwear

12. Constipation – environmental issues • School toilets! • Toilet cold/dark • Toilets dirty • Uncomfortable • Lack of privacy • Lack of toilet paper • inaccessible

13. Assessing constipation • ‘Red flag’ symptoms include: --> 48 hours before passing meconium as a neonate • Abdominal distension esp if failing to thrive • Infrequent small or ribbon stools • Constant leaking especially if linked with urinary leaking too • Failed management with appropriate standard intervention (with compliance)

14. Diagnostic approachHistory • birth history of gestational complications, birthweight, timing of passage of meconium, and tolerance of early feedings. • introduction of cow milk is the most constipating component of the young child’s diet. • Transitions to child care, all-day school, diaper to toilet training • Family history is reviewed for evidence of genetic factors, as aganglionosis, cystic fibrosis, hypothyroidism, neurofibromatosis, or myopathies

15. History (cont.) • The character of the stools is reviewed from birth, especially for the first 24 hours, for consistency, caliber, volume, and frequency. • The age and circumstances at onset of encopresis should be documented. • Encopresis in the absence of constipation suggests an organic or behavioral origin. • A history of possible sexual or rectal abuse should be elicited

16. Physical examination • Documentation of growth and weight gain • Signs of systemic diseases include a thorough neurologic evaluation. • The abdomen is examined for degree of distension Bowel sounds are documented, • perineum is inspected for evidence of encopresis, streptococcal or monilial infection, fissures, and trauma (abuse) • The anal opening is observed, watch for perirectal manifestations of Crohn‘s disease

17. Physical examination (cont.) • A dilated ampulla filled with retained firm stool is a feature of functional retention. • The abdominal examination may demonstrate palpable dilated loops of sigmoid and distal colon. • The back should be examined for sacral skin clues to lower spine deformity. • Tendon reflexes should also be assessed to rule out neurological problem.

18. Treatment of constipation • Demystification with written information • structured toileting programme • consistent scheduled toileting • positive reinforcement • diet / fluid adjustment • oral laxatives • Suppositories/enemas only as very last resort and if tolerated by child

19. Disimpaction: 1 • Assess for faecal impaction • Use history taking and physical examination to diagnose faecal impaction • Look for overflow soiling and/or faecal mass palpable abdominally and/or rectally

20. Disimpaction: 2 • Offer oral medication for disimpaction • Inform families that disimpaction can initially increase: • symptoms of soiling • abdominal pain

21. Maintenance therapy • Offer oral medication for ongoing treatment • Continue maintenance dose after regular bowel habit is established • Reduce the dose over a period of months in response to stool consistency and frequency

22. Diet and lifestyle: 1 • Do not use dietary interventions alone as first-line treatment • Treat constipation with: • laxatives • negotiated non-punitive behavioural interventions • dietary modifications and sufficient fluid consumption