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Some Physical Causes and Features of Constipation in Infants and Children

Some Physical Causes and Features of Constipation in Infants and Children


Common Features*


Birth defects of the anus

Abnormal position of the anus

Opening of the anus that appears closer than normal to the genitals

Measurements to determine the exact location of the anus’s opening

Anal stenosis (a narrowed anus)

Delayed passage of the first BM (called meconium) during the first 24–48 hours of life

Explosive and painful BMs

A swollen abdomen

Abnormal appearance or position of the anus

A doctor's examination

Blockage of the opening of the anus (anorectal malformations)

A swollen abdomen

No BMs

A blockage of the anus detected during a doctor's examination

A doctor's examination done soon after birth

Spinal cord problems

Meningomyelocele (the most severe form of spina bifida)

A raw, red area on the back where the spinal cord protrudes, seen at birth

A decrease in reflexes of the legs or in muscle tone

Absence of the normal reflex of the anus (a tightening when lightly touched, called anal wink)

Plain x-rays of the lower spine

MRI of the spine

Occult spina bifida (incomplete formation of the bones of the spine)

Possibly a tuft of hair or dimpling on the skin over the defect, seen at birth

MRI of the spine

A tethered spinal cord (during fetal development, the spinal cord is stuck at the lower end of the spinal column and cannot move up to its normal position)

Problems with walking, pain or weakness in the legs, and back pain

Urinary incontinence

MRI of the spine

A tumor near the tailbone (sacral teratoma) or other spinal cord tumor

Back pain, problems with walking, and pain or weakness in the legs

Urinary incontinence

MRI of the spine

Infection of the spine or spinal cord

Back pain, problems with walking, and pain or weakness in the legs


Urinary incontinence

MRI of the spine

Hormonal, metabolic, or electrolyte disorders

Diabetes insipidus (due to problems with antidiuretic hormone, which helps regulate the amount of water in the body)

Excessive thirst and excessive crying that is quieted by giving children water

Excessive urination of dilute urine

Weight loss and vomiting

Urine and blood tests to measure how dilute urine and blood are (osmolality)

Blood tests to measure antidiuretic hormone levels

Hypercalcemia (an abnormally high calcium level in the blood)

Nausea and vomiting, loss of appetite, weight loss, muscle weakness, and abdominal pain

Excessive thirst and excessive urination

Blood tests to measure the calcium level

Hypokalemia (an abnormally low potassium level in the blood)

Muscular weakness

Excessive urination and dehydration

Not growing as expected (failure to thrive)

Possibly use of diuretics or certain antibiotics

Blood tests to measure levels of electrolytes

Hypothyroidism (an underactive thyroid gland)

Poor feeding

A slow heart rate

In newborns, large soft spots (fontanelles) between the skull bones and slack muscle tone

Dry skin, intolerance of cold, fatigue, and jaundice

Blood tests to measure thyroid hormone levels

Intestinal disorders

Delayed passage of the first BM

Poor weight gain or failure to thrive

Frequent bouts of pneumonia

A sweat test

Possibly genetic testing to confirm the diagnosis

Delayed passage of the first BM

A swollen abdomen

Green or yellow vomit, indicating that it contains bile

A narrowed anus detected during a doctor's examination

X-rays of the lower digestive tract after barium is inserted in the rectum (barium enema)

Measurement of pressure inside the anus and rectum (manometry)

Biopsy of the rectum


Poor feeding

Weight loss, poor growth, or both

Blood in stools

Stool tests

Symptoms that lessen when the formula is changed

Possibly endoscopy, colonoscopy, or both

Abdominal pain


Weight loss


Blood tests


Long-standing (chronic) abdominal pain

Diarrhea and constipation that come and go

A feeling of incomplete emptying after a BM

Evaluation of BM patterns and the timing and characteristics of pain

Exclusion of other disorders by history, physical examination, and possibly blood tests, stool tests, imaging, or colonoscopy

Pseudo-obstruction (which causes symptoms of a blockage but no blockage is detected)

Nausea and vomiting

Abdominal pain and a swollen abdomen

X-ray of the abdomen

Tests to assess how well the bowel functions (bowel motility studies)

A tumor in the abdomen

Weight loss, night sweats, and fever

Abdominal swelling or pain

An abdominal mass detected during a doctor's examination


Drug side effects

Use of drugs with anticholinergic effects(such as antihistamines), antidepressants, chemotherapy drugs, or opioids

Use of drugs that can cause constipation

A doctor's examination


A sudden reduction in the ability to suck

Loss of muscle tone

Sometimes consumption of honey before age 12 months

A test for botulinum toxin in stool

Usually no symptoms

Possibly abdominal pain, fatigue, and irritability

Regression in development

Blood tests to measure the lead level

* Features include symptoms and results of the doctor's examination. Features mentioned are typical but not always present.

BM = bowel movement; MRI = magnetic resonance imaging.