Good Morning!Tuesday, April 3rd 2012

Causes of Constipation

Nonorganic

Functional fecal retention

Anatomic

Anal stenosis

Imperforate anus

Anteriorly displaced anus

Intestinal stricture (post NEC)

Abnormal musculature

Prune-belly

Gastroschisis

Down syndrome

Intestinal Nerve/Muscle Abnormalities

Hirschsprung disease

Pseudo-obstruction

Intestinal neuronal dysplasia

Spinal Cord Defects

Tethered Cord

Spinal cord trauma

Spina bifida

Causes of Constipation

Drugs

Anticholinergics

Narcotics

Antidepressents

Chemotherapy

Pancreatic enzymes

Lead

Vitamin D intoxication

Metabolic Disorders

Hypokalemia

Hypercalcemia

Hypothyroidism

Diabetes Mellitus

Intestinal Disorders

Celiac disease

Cow’s milk protein intolerance

Cystic fibrosis

Inflammatory bowel disease

Tumor

Connective Tissue Disorders

SLE

Scleroderma

Psychiatric Disorders

Anorexia nervosa

Constipation

5% of all outpatient pediatric visits25% of referrals to pediatric GIDefinition:

◦Infrequent bowel evacuation◦Hard small feces◦Difficult or painful evacuation of large-diamter

stools◦Fecal incontinence (encopresis)

Its all relative◦A child with 3 small stools a day may not have

evacuated colon, but a child with 2 large soft stools a week is not constipated

Normal Stooling Patterns

90% of newborns pass meconium in 1st 24 hours

Intestinal transit time◦8 hours = 1 month◦16 hours = 2 years◦26 hours = 10 years

Infant dyschezia◦10 minutes of straining and crying before

successful passage of soft stool in otherwise healthy infant; failure of pelvic floor to relax; resolves spontaneously

Vicious cycle of constipation

Repetitive denial of evacuation due to pain leads to stretching of rectum and lower colon

Reduction in muscle tone Retention of stoolLonger the stool remains in rectum, more

water is removed, harder the stool becomes to point of impaction

Functional Constipation

Accounts for 95% of casesPersistent, difficult, infrequent, or

incomplete defecation without evidence of anatomic or biochemical cause

Peaks in pre-school years3 periods prone to constipation:

◦Introduction of cereals and solid foods◦Toilet training◦Start of school

Functional Constipation (cont’d)

Toddlers and older children may withhold stool:◦Painful defecation◦Avoid defecation in a strange toilet away from

home◦Too distracted (ADHD)

Symptoms:◦Early satiety, desire to eat small volumes all

day, increasing irritability, spasms of abdominal pain in lower abdomen

Question

A 5-year-old girl has a confirmed urinary tract infection. She has had 4 UTIs in the past 2 years, which all resolved with antibiotics. She denies urgency and frequency. The only significant history is constipation. Renal U/S and VCUG are normal. Her growth is normal. You prescribe Bactrim.

Of the following, the MOST appropriate additional step to reduce future UTIs is:◦ A. Begin evaluation for immunodeficiency◦ B. Perform renal scintigraphy◦ C. Prescribe stool softener and regular bowel routine◦ D. Prescribe oral oxybutynin◦ E. Refer to pediatric nephrologist

History

Passage of meconiumTransitions: breastmilk to formula to cow’s

milk; child care to all-day school; diapers to toilet training

Family historyCharacter of stoolsEncopresisPast medical historyMedications*Urinary incontinence

Physical Exam

Growth and weight gainUmbilical girthAbdominal exam

◦Bowel sounds◦Palpable dilated loops

Rectal exam◦Distended rectum full of stool

Back (look for sacral skin findings)

Laboratory

Plain abdominal radiographThyroid function, electrolyte levels, magnesium*UA, urine cultureLumbosacral spine films/MRIBarium enemaLead levelMotility testing

◦Colon transit studies◦Anorectal manometry◦Consider in pts. with no organic cause of

constipation, but failure to respond to aggressive treatment

*Hirschsrung Disease

Lack of ganglion cells in the myenteric and submucosal plexus of bowel wall

Onset of symptoms in 1st week of lifeDelayed passage of meconium (after 48

hours)Abdominal distentionVomitingTransition zone on enemaFailure to thriveAcute enterocolitis60% diagnosed by 3 months of ageAbsence of encopresis

Hirschsprung Disease

Encopresis

Repeated involuntary fecal soiling in the underpants

Children should obtain fecal continence by the age of 4◦*Encopresis is a symptom rather than a

developmental variation after age 4 to 590% is functional

◦Retentive constipation with overflow incontinence

*5 to 10% is organic, behavioral, environmental (privacy issues)◦Anatomic, neurologic, metabolic, iatrogenic

Management of Chronic Constipation and Encopresis

Phase 1: Disimpaction

Management of Chronic Constipation and Encopresis

Phase 2: Maintenance◦Pattern of daily defecation should be maintained◦The goal is to maintain soft bowel movements

once or twice a day◦This phase can last from 2 to 6 months or longer

Months are required for rectum to return to normal caliber and regain normal sensation

◦*Best approach is a combination of medical therapy, behavioral modification, and counseling

*

Management of Chronic Constipation and Encopresis

Behavior modification◦Patient should sit on

toilet for 10 minutes after meals 2-3 times/day

◦A footstool may be used to help improve the Valsalva maneuver

◦“Star” charts

Behavior Modification

Anorectal dyssynergia◦Paradoxic increase in external sphincter tone

while trying to defecate◦Diagnosed with anorectal manometry◦Patients are candidates for biofeedback therapy

with manometry

Management of Chronic Constipation and Encopresis

Phase 3: Weaning From Medication◦Start when child consistently is achieving 1 to 2

soft bowel movements daily◦Usually after 6 months◦Wean stimulant laxatives first, then lubricant or

osmotic agents

Management of Chronic Constipation and Encopresis

Diet◦High-fiber diet

Shown to increase number of bowel movements and decrease episodes of encopresis

Avoid until child is no longer withholding stool, because bulking with fiber may lead to additional withholding

Whole grains, fruits, and vegetablesProbiotics

◦Have been shown to improve colonic transit time◦More studies are needed

Relapse

Patients who show no improvement after 6 months should be referred to GI

*Relapses are common! Rates of recurrence approach 50%