Enemas, Oral Laxatives Equally Effective for Childhood Fecal Impaction

MedscapeCME Clinical Briefs

News Author: Laurie Barclay, MD
CME Author: Penny Murata, MD

December 22, 2009 — Enemas and orally administered laxatives are equally effective in treating rectal fecal impaction (RFI) in functional childhood constipation, according to the results of a randomized controlled trial reported in the December issue of Pediatrics.

"Despite a lack of scientific data, rectal enemas have long been advocated as the best first-line treatment for RFI," write Noor-L-Houda Bekkali, MD, from Academic Medical Centre in Amsterdam, Netherlands, and colleagues. "Two studies showed that oral [polyethylene glycol (PEG)] treatment yielded 95% successful disimpaction....This is the first prospective, randomized, controlled trial evaluating disimpaction with either rectal enemas or orally administered laxatives for children with severe RFI attributable to constipation."

The hypothesis tested by this study was that enemas and PEG would be equally effective in treating RFI but that enemas would be less well tolerated and colonic transit time (CTT) would improve during disimpaction.

The study sample consisted of 90 children (from 95 who were eligible), aged 4 to 16 years, with functional constipation and RFI. Rectal examination and first CTT measurement were performed, and symptoms of constipation were recorded 1 week before disimpaction. Patients with RFI were randomly assigned to treatment with once-daily enemas or with PEG (1.5 g/kg per day) for 6 consecutive days.

A second CTT measurement was performed during this treatment, as well as a child's behavior questionnaire. Other outcomes included successful rectal disimpaction, frequencies of defecation and fecal incontinence, and presence of abdominal pain and watery stools.

Mean age was 7.5 ± 2.8 years. Of the 90 participants, 60 were boys; 46 were assigned to enema treatment and 44 to PEG, with 5 dropouts in each group. Disimpaction was successful in 80% of patients in the enema group and 68% of the PEG group (P = .28).

Although fecal incontinence and watery stools occurred more often in the PEG group (P < .01), both groups had similar frequency of defecation (P = .64), abdominal pain (P = .33), behavior scores, and CTT normalization (P = .85).

"Enemas and PEG were equally effective in treating RFI in children," the study authors write. "Compared with enemas, PEG caused more fecal incontinence, with comparable behavior scores. The treatments should be considered equally as first-line therapy for RFI."

Limitations of this study include possible confounding of findings regarding fearful behavior and evaluation of behavior scores only after the start of disimpaction.

"Given the comparable behavior in the 2 groups, disimpaction with enemas should not necessarily be withheld to prevent anxiety," the study authors conclude. "We did not find more fearful behavior in the enema group, which might be explained by the administration of enemas by parents at home instead of by nurses in an unfamiliar environment (hospital), which is more common in practice."

The study authors have disclosed no relevant financial relationships.

Pediatrics. 2009;124:e1108-e1115. Abstract

Clinical Context

The worldwide prevalence of functional constipation in children is 7% to 30%, according to van den Berg and colleagues in the October 2006 issue of the American Journal of Gastroenterology. RFI refers to a large fecal mass on abdominal palpation or rectal examination that is unlikely to be passed on demand, as reported by Benninga and colleagues in the March 2005 issue of the Journal of Pediatric Gastroenterology and Nutrition. Treatment options for RFI include enemas, manual evacuation, and PEG.

This randomized controlled trial assesses the efficacy, effect on CTT, and tolerability of enema vs PEG treatment of RFI in children with functional constipation.