Sacral agenesis and fecal incontinence: how to increase the index of suspicion.

Purpose: Sacral abnormalities range from missing the coccyx, a few sacral vertebrae, or hemi-sacrum, to complete absence with fused iliac bones. The purpose of this study was to review the association between sacral agenesis and fecal incontinence to help inform patient prognosis.
Methods: A retrospective review was performed of patients who presented for bowel management due to sacral agenesis at a tertiary care children's hospital between 2016 and 2017 (n = 10). Data collection included: gender, time of diagnosis, sacral ratio, and associated anomalies. Patients with anorectal malformation and sacrococcygeal teratomas were excluded.
Results: Four patients were female. Seven patients had a delayed diagnosis ranging from 22 months of age to 9 years. Most common symptoms included failure of age-appropriate toilet training and severe diaper rash. The sacral ratio was zero (6), 0.3 and 0.4 (2), and hemi-sacrum (2). Associated anomalies were present in five patients.
Conclusion: Sacral abnormalities should be suspected in patients who present with early severe diaper rash and those who fail to toilet train. An abdominal radiograph can evaluate the sacrum, when the sacral ratio is 0.4 or less, parents should be counseled regarding fecal incontinence and neurogenic bladder.