Organic Causes of Constipation in Infants and Children
Cause | Suggestive Findings | Diagnostic Approach |
|---|---|---|
Anatomic | ||
Anal stenosis | Delayed passage of stool in the first 24–48 hours of life Explosive and painful stools Abdominal distention Abnormal appearance or position of the anus Tight anal canal detected by digital examination | Clinical evaluation |
Anteriorly displaced anus | Severe chronic constipation with marked straining and pain when stool is passed Typically no response to aggressive use of stool softeners and cathartics Anal opening not located in the center of the pigmented area of the perineum | Calculation of anal position index* indicating anterior placement, which varies by sex:
|
Abdominal distention No passage of stool Abnormal appearance or position of the anus or possibly no anus | Clinical examination | |
Endocrine or metabolic disorders | ||
Polydipsia Polyuria Excessive crying quieted with water intake Weight loss Vomiting | Urine and serum osmolality Antidiuretic hormone levels Serum sodium Sometimes water deprivation test | |
Nausea, vomiting Muscle weakness Abdominal pain Anorexia, weight loss Polydipsia Polyuria | Serum calcium | |
Muscular weakness Polyuria, dehydration History of growth failure | Electrolyte panel | |
Poor feeding Bradycardia Large fontanelles and hypotonia in neonates Cold intolerance, dry skin, fatigue, prolonged jaundice | Thyroid-stimulating hormone (TSH) Thyroxine (T4) | |
Spinal cord defects | ||
Grossly visible lesion in vertebral spine at birth Decrease in lower-extremity reflexes or muscular tone Absence of anal wink | Plain x-rays of lumbosacral spine Spinal MRI | |
Possibly sacral hair tuft or pit | Spinal MRI | |
Tethered cord | Change in gait Pain or weakness in lower extremities Urinary incontinence Back pain | Spinal MRI |
Spinal cord tumor or infection | Back pain Pain or weakness in lower extremities Decrease in lower-extremity reflexes Change in gait Urinary incontinence | Spinal MRI |
Intestinal disorders | ||
Celiac disease (gluten enteropathy) | Symptom onset after introduction of wheat into diet (typically after age 4–6 months) Failure to thrive Recurrent abdominal pain Bloating Diarrhea or constipation | Complete blood count Serologic screening for celiac disease (IgA antibody to tissue transglutaminase) Endoscopy for duodenal biopsy |
Cow's milk protein intolerance (milk protein allergy) | Vomiting Diarrhea or constipation Hematochezia Anal fissures Failure to thrive | Symptom resolution with elimination of cow's milk protein Sometimes endoscopy or colonoscopy |
Delayed passage of meconium or meconium ileus in the neonate Possible repeated episodes of small-bowel obstruction (meconium ileus equivalent) in older children Failure to thrive Repeated episodes of pneumonia or wheezing | Sweat test Genetic testing | |
Delayed passage of meconium Abdominal distention Tight anal canal detected by digital examination | Barium enema Anorectal manometry and rectal biopsy for confirmation | |
Chronic recurrent abdominal pain Often alternating diarrhea and constipation Feeling of incomplete evacuation Passage of mucus No anorexia or weight loss | Clinical evaluation | |
Intestinal pseudo-obstruction | Nausea, vomiting Abdominal pain and distention | Abdominal x-ray Colonic transit time Antroduodenal manometry |
Intestinal tumor | Weight loss Night sweats Fever Abdominal pain and/or distention Palpable abdominal mass Bowel obstruction | MRI |
Cerebral palsy and other severe neurologic deficits | In most children with cerebral palsy, which causes intestinal hypotonia and motor paralysis Tube feedings with low-fiber formulas | Clinical evaluation |
Drug adverse effects | ||
Use of anticholinergics, antidepressants, chemotherapeutics, or opioids | Suggestive history | Clinical evaluation |
Toxins | ||
New onset of poor suck, feeding difficulties, anorexia, drooling Weak cry Irritability Ptosis Descending or global hypotonia and weakness Possible history of ingestion of honey before age 12 months | Test for botulinum toxin in stool | |
Most likely asymptomatic Possible intermittent abdominal pain, sporadic vomiting, fatigue, irritability Loss of developmental milestones | Blood lead level | |
* Anal position index (API) is calculated as follows:
| ||
SD = standard deviation. | ||