A 6-year-old girl is brought to clinic by her mother due to constipation. Over the last 8 months, the patient's stools have become much more formed and less frequent. She now has large-caliber stools that clog the toilet every 4-5 days and are painful to pass. Her mother has been giving her daily stool softeners over the last month, without improvement. Twice in the last 2 weeks, the patient has had some drops of blood in the toilet after stooling, which prompted the clinic visit. She has been eating well with no associated vomiting, but her mother says that the patient is sometimes picky. Height is 111 cm (3 ft 8 in) and weight is 17.7 kg (39 lb), unchanged from her last well-child check 10 months ago. Temperature is 37 C (98.6 F) and pulse is 70/min. The patient is well-appearing. There is mild abdominal distension and a small anal fissure at the posterior commissure of the anus; the remainder of the examination is normal. Which of the following is most concerning for a pathologic, rather than a functional, cause of constipation in this patient?
Pediatric constipation | ||
Pathologic | Functional | |
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*Benign features refractory to functional constipation management may also be pathologic. | ||
Functional constipation, or hard and infrequent defecation without a serious underlying condition, is the most common cause of chronic constipation in children. However, this patient with poor weight gain and linear growth most likely has pathologic constipation.
Pathologic constipation is due to a serious organic cause and can often be identified with a focused history and physical examination alone. Failure of symptom improvement after treatment for functional constipation (ie, increased fiber, laxatives), as seen in this patient, should raise suspicion for an underlying organic cause. Additional risk factors include Down syndrome, which increases the risk of Hirschsprung disease (HD) and intestinal stenosis/atresia, and a history of delayed meconium passage, which is strongly associated with HD or cystic fibrosis.
Red flags suggestive of pathologic constipation include lower extremity neurologic symptoms (eg, weakness) and sacral anomalies (eg, hair tuft) concerning for spinal dysraphism, as well as a history of poor growth. In this case, poor weight gain in the setting of constipation warrants consideration of celiac disease, cystic fibrosis, or hypothyroidism. Poor linear growth, in particular, is concerning for hypothyroidism, which can also present with lethargy, cold intolerance, and dry skin.
(Choices A, C, D, and E) Features seen in both functional and pathologic constipation include painful, infrequent defecation with large-caliber stools, leading to anal fissures, and rectal bleeding. Mild abdominal distension and left lower quadrant firmness or palpable stool in the rectal vault may also be present due to stool retention. In contrast, severe abdominal distension, ribbon-caliber stools, and rectal bleeding in the absence of an anal fissure or hemorrhoid, none of which are seen in this patient, are not features of functional constipation and may warrant evaluation for intestinal obstruction/stenosis.
Educational objective:
Although functional constipation is the most common cause of constipation in children, alarm signs such as poor growth, delayed passage of meconium, and abnormal physical findings (eg, sacral anomalies) should trigger evaluation for pathologic causes.