An association between infantile hypertrophic pyloric stenosis (IHPS) and concomitant urinary tract infection (UTI) has been reported previously.1 Two consecutive infants with IHPS who continued to vomit after successful surgical and medical treatment in our institution were found to have concomitant UTI.

This prompted us to examine all cases of radiologically proven IHPS diagnosed in our hospital in whom vomiting, which may be a manifestation of UTI in infants, did not resolve after surgical treatment, to assess the possibility that concomitant UTI is the cause for post-pyloromyotomy emesis in IHPS infants. We examined all records of IHPS patients aged 2 to 7 weeks admitted to our hospital during a 10 year period between 1985 and 1995.

In all, 170 infants (138 male, 32 female) who presented within the first seven weeks of life (mean 4.4 (2.6) weeks) with progressively worsening emesis and clinical signs compatible with IMPS, had radiological confirmation of the diagnosis and underwent Ramstedt pyloromyotomy.

Of them, 24 (14.1%) patients had post-pyloromyotomy emesis and were evaluated for the possibility of UTI; urine analysis and cultures were obtained by either suprapubic aspiration or bladder catheterisation. If urine analysis suggested the presence of UTI, empiric antibiotic therapy was initiated with urine culture until urine culture results were obtained.

Four patients (three male, one female) out of 24 post-pyloromyotomy emesis patients (16.6%) were found to have concomitant clinically manifested UTI and IMPS. Symptomatic UTI occurs in 0.14% of live newborns.2

In a previous report of 276 infants with IMPS, two of them (0.72%) had confirmed UTI.1 In our series of 170 IHPS patients, four of them (2.35%) were found to have concomitant UTI, clinically manifested by continuity of vomiting after surgical repair of the IHPS.

This figure is 17-fold higher than the expected incidence of UTI in young infants and it makes one wonder about the true aetiology of vomiting at the presentation of symptoms. Thus, as post-pyloromyotomy emesis occurs in 5–15% of surgically treated infants,3we recommend that any child who continues to vomit after adequate surgical treatment of IHPS be evaluated for the possibility of concomitant UTI.