Constipation%20in%20children Diagnosis

Types of Constipation

• Functional/idiopathic constipation
  • Constipation that cannot be explained by any anatomical, physiological, radiological or histological abnormalities
• Organic constipation
  • Constipation with an identifiable physiological or organic cause; presence of red and/or amber flags
• Chronic constipation
  • Constipation lasting for >8 weeks

• When thorough and complete, the history and physical exam findings are usually sufficient to allow the healthcare professional to decide if the child has functional constipation or needs further evaluation
• The younger the infant, the higher the risk of an anatomic or organic cause of constipation
• Establishing whether constipation is functional or organic helps direct diagnostic tests and treatment plan
• Organic causes of constipation in infants and children have warning signs or “red flags”

• The following key components are essential in history taking:
  
  • Children <1 year old
    
    • Stool patterns (<3 complete stools/week, hard large stool, “rabbit droppings”)
    • Symptoms associated with defecation (distress while defecating, bloody hard stools, straining)
    • Previous history of constipation or previous/current anal fissure
  • Children >1 year old
    
    • Stool patterns (<3 complete stools/week, overflow soiling, “rabbit droppings”, large hard infrequent stools)
    • Symptoms associated with defecation (poor appetite that improves with passage of large stool, waxing and waning of abdominal pain with passage of stool, straining, anal pain)
    • Previous episode(s) of constipation, previous/current anal fissure, painful bowel movements with bleeding associated with hard stools)
• Medical history taking should also include previous treatment (diet, medications, adherence), family history, medical history (time of passage of meconium, condition at birth, growth), developmental history (school performance), and psychosocial history (family and peer interactions, temperament)

• Perform a complete physical examination with focus on the abdomen (distention, palpate liver and spleen, fecal mass), anus (position, presence of stool, erythema, skin tags, fissures), rectum (anal wink, anal tone, fecal mass, presence and consistency of stool, explosive stool on removal of finger), back and spine (dimple, tuft of hair), neurology (tone, strength, cremasteric and deep tendon reflexes)
• A digital rectal exam (DRE) is done to assess tone in the rectum and presence of impaction
  
  • A DRE should be done only by healthcare professionals capable of interpreting anatomical abnormalities or diagnosing Hirschsprung’s disease
  • Not to be performed in children >1 year with red flag signs/symptoms
  • Advisable for <1-year-old patients diagnosed with idiopathic constipation unresponsive to optimum treatment within 4 weeks
  • No confirmatory imaging tests are indicated if fecal impaction is present on DRE
  • An abdominal X-ray may be needed if a rectal exam cannot be done or is traumatic for the child

“Red Flag” Signs Indicative of Organic Constipation

• Perianal area
  
  • Abnormal appearance/position/patency of anus: Fistulae, bruising, multiple fissures, tight or patulous anus, anteriorly placed anus, absent anal wink, pilonidal dimple

• Abdominal exam
  
  • Gross abdominal distention
  • Tight, empty rectum in presence of palpable abdominal fecal mass

• Spine/lumbosacral region/gluteal exam
  
  • Abnormal asymmetry or flattening of the gluteal muscles, evidence of sacral agenesis, discolored skin, nevi or sinus, hairy patch, lipoma, central pit, scoliosis

• Lower limb neuromuscular exam
  
  • Deformity (eg talipes)
  • Decreased lower extremity tone and/or strength
  • Abnormal reflexes (absent cremasteric reflex, absence or delay in relaxation phase of lower extremity deep-tendon reflexes)

Hirschsprung’s Disease

• Most common cause of obstruction in the lower intestines in neonates and a rare cause of difficult-to-control constipation in children ≥2 years
• Suspected when the following is present: Meconium passage ≥48 hours after birth, small stools, failure to thrive, fever, bloody diarrhea, bilious vomiting, tight anal sphincter, and palpable fecal mass in the abdomen with empty rectum

Spinal Cord Abnormalities

• Eg tethered cord, spinal cord tumor
• May be considered if there is presence of decreased lower extremity reflexes or muscular tone, negative anal wink, positive pilonidal dimple or hair tuft

Hypothyroidism

• Suspected if there is fatigue, intolerance to cold, slow heart rate, poor growth

Diabetes Insipidus

• May be considered if there is increased urination and thirst

Cystic Fibrosis

• Suspected if there is diarrhea, failure to thrive, rash, fever, recurrent pneumonia

Anal Abnormalities

• Eg congenital anorectal malformation, imperforate anus, anal stenosis
• Suspected if there are physical exam findings of abnormal position or appearance of anus

• Generally unnecessary unless in confirming alternative diagnosis or organic causes of constipation
• Unless an organic disease is suspected from history and physical exam and the child is unresponsive to adequate treatment, it is generally not necessary to have laboratory studies
• Fecal occult blood tests may be done in infants and children with constipation who have diarrhea, abdominal pain, failure to thrive, or positive family history of colorectal cancer or polyps
• Organic, metabolic, and endocrine diseases can be confirmed by performing thyroxine, thyroid stimulating hormone (TSH), calcium and lead levels, celiac disease antibodies, and a sweat test

Abdominal Radiography

• May be used for assessing fecal impaction in children with inconclusive medical history and physical exam
• Shows the amount of stool present
• Useful in obese children and those who cannot have a digital rectal exam (DRE) done
• Has limited value in clinically assessing constipation due to poor correlation between radiological and clinical diagnosis

Anorectal Manometry (ARM)

• Directly measures the sensorimotor function (eg resting pressure, inhibitory reflex, squeeze pressure) of the anus and rectum
• Indicated for patients suspected of Hirschsprung disease, rectal outlet obstruction, and patients with history of surgery for Hirschsprung disease or imperforate anus

Barium Enema

• A contrast dye (barium) coats the lining of the bowel for clear visualization on an X-ray
• Useful in diagnosing Hirschsprung’s disease by demonstrating the transition zone (change in diameter of the colon from the narrow aganglionic segment to a dilated ganglionic segment)
• Helps evaluate motility of colon (slow motility in megasigmoid and impacted stool)
• Less reliable during the 1st months of life due to insufficient dilation of the proximal colon for the transition zone to be demonstrable

Colon Transit Time (Radiopaque Markers) Studies

• Involves swallowing of a capsule containing radiopaque markers followed by serial X-rays taken over several days
• Most markers are removed by the 5th day and delayed removal indicates slow motility of the colon
• Useful in children with chronic difficult-to-control constipation and in children with bowel movements that are infrequent and negative signs of constipation

Colonic Manometry

• Measures intraluminal pressure throughout the length of the colon to identify motility deficits and dysfunction using a catheter inserted endoscopically or via fluoroscopic guidance
• May be used for children with intractable constipation considering surgical interventions

Rectal Biopsy

• A small sample of a full-thickness biopsy is taken about 3 cm above the anal verge
• Definitive means of diagnosing Hirschsprung’s disease
• Presence of hypertrophied nerves on microscopy establishes the diagnosis of Hirschsprung’s disease
• Not indicated when clinical and imaging findings are suggestive of functional constipation

Other Tests

• Magnetic resonance imaging (MRI) of the lumbosacral spine can identify intraspinal problems like sacral agenesis, tumors, or a tethered cord
• Flexible sigmoidoscopy and colonoscopy can demonstrate colonic structural problems like fissures, tumors, or strictures
• Further studies are needed to prove the use of wireless motility capsule and barostat in the assessment of pediatric constipation

• Constipation that cannot be explained by any anatomical, physiological, radiological or histological abnormalities
• Also known as idiopathic constipation, functional fecal retention or fecal withholding
• Most common cause of constipation
• Commonly caused by painful bowel movements with resultant voluntary withholding of feces by a child who wants to avoid unpleasant defecation
• Present if the following are detected:
  
  • History: Passage of stool within 2 days of birth, hard large-caliber stools, encopresis, painful defecation, bloody stools, decreased appetite, abdominal pain with bowel movement, diet low in fluid and fiber, high in milk products, avoids the toilet
  • Physical exam: Normal appearance of the anus and the surrounding area, soft or mild distention of the abdomen, stool palpable in the left lower quadrant, normal anal placement and sphincter tone, rectum distended and filled with stool, positive anal wink and cremasteric reflex

• Rome IV diagnostic criteria for functional constipation in infants and children up to 4 years of age:
  
  • ≥2 of the following present for at least 1 month:
    
    • Two or fewer defecations per week
    • History of retentive posturing or excessive volitional stool retention
    • History of painful or hard bowel movements
    • Presence of a large fecal mass in the rectum
    • History of large diameter stools that may obstruct the toilet
  • For children already potty-trained, additional criteria are as follows:
    • Incontinence of ≥1 episode/week after learning toilet skills
    • History of large-diameter stools causing toilet clogging

• Rome IV diagnostic criteria for functional constipation in children and adolescents ≥4 years of age:
  
  • ≥2 of the following present for at least once per week for at least 1 month:
    
    • Two or fewer defecations per week
    • At least 1 episode of fecal incontinence per week
    • History of retentive posturing or excessive volitional stool retention
    • History of painful or hard bowel movements
    • Presence of a large fecal mass in the rectum
    • History of large diameter stools that may obstruct the toilet
  • Above symptoms unrelated to another disease