Rectal compliance and rectal sensation in constipated adolescents, recovered adolescents and healthy volunteers

OBJECTIVES

A subgroup of children with functional constipation (FC) are unresponsive to conventional treatment. Abnormal rectal function due to increased distensibility (compliance) might be an underlying mechanism of therapy-resistant FC. It is hypothesised that rectal compliance is normal in patients who are successfully recovered from FC (RC).

METHODS

Using a barostat, a pressure-controlled intermittent distension protocol was performed in FC patients, RC subjects free of symptoms for at least 4 years and healthy volunteers (HVs). Rectal compliance was calculated using a non-linear mixed-effect model for volume-pressure curves.

RESULTS

Forty-seven FC patients, median (range) age of 12 (11-17) years, and 20 RC subjects, 15 (11-18) years, were studied and compared with 22 HVs, 14 (8-16) years. The median (5th-95th percentile) rectal compliance in HVs was 16 (12-20) ml/mm Hg. FC patients had a median rectal compliance of 25 (13-47) ml/mm Hg and RC subjects 20 (12-35) ml/mm Hg, which was significantly higher compared with HVs (p<0.001 and p = 0.003). RC subjects had lower rectal compliance when compared with FC patients (p = 0.02). Forty-five percent of RC subjects had a rectal compliance above the upper limit of normal (>95th percentile of HVs), which was significantly less compared with 75% of FC patients (p = 0.02).

CONCLUSION

While rectal compliance in RC subjects is lower when compared with adolescents with FC, almost half of the RC subjects showed an increased rectal compliance. The role of rectal compliance in therapy-resistant FC seems limited, because recovery is possible despite an increased rectal compliance.

Assessment of the rectoanal inhibitory reflex in preterm infants with delayed meconium passage

BACKGROUND

There is an inverse relationship between gestational age, birth weight and the time of first neonatal bowel movement. The authors hypothesized that delayed passage of meconium might result from a delayed maturation of the recto-anal inhibitory reflex (RAIR) in premature infants.

OBJECTIVE

To evaluate whether the RAIR is absent in very preterm infants 28-32 weeks postmenstrual age with delayed meconium production.

STUDY DESIGN

Anorectal manometry was performed in 10 preterm infants (seven male) with delayed meconium production (no meconium in the first 48 hours). Median postmenstrual age was 30 weeks (28-31 weeks). Birth weight ranged from 780 to 1930 g (median, 1395 g). A micromanometric assembly (outer diameter, 2.0 mm) was used which incorporated a 1.5-cm-long sleeve sensor for measurement of resting anal sphincter pressure and relaxation. Four side-holes recorded anal and rectal pressures. Rectal distension was performed with direct air insufflation to elicit the RAIR.

RESULTS

The time from birth to passage of meconium ranged from 48 to 105 hours (median, 82 hours). The mean anal sphincter pressure, rectal pressure, and anal sphincter oscillation frequency were 22.0 +/- 5.0 mm Hg, 6.9 +/- 2.0 mm Hg, and 9.8 +/- 1.9/min, respectively. A normal RAIR was elicited in all infants.

CONCLUSION

Anorectal manometry recordings in premature infants with delayed passage of meconium showed normal anorectal pressures and a normal RAIR, suggesting that delayed meconium passage is not related to the absence of a RAIR.

Health related quality of life in disorders of defecation: the Defecation Disorder List

BACKGROUND

Constipation and encopresis frequently cause problems with respect to emotional wellbeing, and social and family life. Instruments to measure Health Related Quality of Life (HRQoL) in these disorders are not available.

METHODS

A disease specific HRQoL instrument, the "Defecation Disorder List" (DDL) for children with constipation or functional non-retentive faecal soiling (FNRFS) was developed using accepted guidelines. For each phase of the process, different samples of patients were used. The final phase of development included 27 children. Reliability was assessed in two ways: internal consistency of domains with Cronbach's alpha, and test-retest reliability with intra-class correlation coefficients (ICC). To assess validity, comparable items and domains were correlated with Tacqol, a generic HRQoL instrument for children (TNO-AZL).

RESULTS

In the final phase of the development, 27 children completed the instrument. It consisted of 37 items in four domains. The response rate was 96%. Reliability was good for all domains, with Cronbach's alpha values ranging from 0.61 to 0.76. Measures of test-retest stability were good for all four domains with ICCs ranging from 0.82 to 0.92. Validity based on comparison with the Tacqol instrument was moderate.

CONCLUSION

The DDL is promising as a measure of HRQoL in childhood defecation disorders.

Colonic transit times and behaviour profiles in children with defecation disorders

AIMS

To evaluate children referred for defecation disorders using the child behavioural checklist (CBCL).

METHODS

A total of 215 patients were divided into three groups: 135 (5-14 years of age) with paediatric constipation (PC), 56 (5-17 years) with functional non-retentive faecal soiling (FNRFS), and 24 (5-16 years) with recurrent abdominal pain (RAP). Behavioural scores were correlated with colonic transit time (CTT) and anorectal function parameters (manometry and EMG).

RESULTS

No significant differences in the mean CBCL scores were found among the three patient groups. However, children with PC and FNRFS had significantly more behavioural problems than the Dutch normative sample, while children with RAP had scores within the normal range. No significant differences were found between CTT in the patient groups, with respect to the CBCL. Similarly, no significant difference existed between children able or unable to relax their pelvic floor muscles during defecation attempts and their behaviour profiles.

CONCLUSION

There seems to be no relation between colonic/anorectal function and specific behavioural profiles. On the other hand, children with defecation disorders show more behavioural problems than do controls.

Alterations in rectal sensitivity and motility in childhood irritable bowel syndrome

BACKGROUND & AIMS

Children with chronic abdominal pain have a heterogeneous clinical presentation, but no organic cause can be identified in most of them. Some children present with symptoms of irritable bowel syndrome (IBS). We hypothesized that visceral hypersensitivity and motor abnormalities may be underlying mechanisms in these children.

METHODS

Rectal sensation and rectal contractile response to a meal were studied in 8 children with IBS and 8 children with functional abdominal pain (FAP) and were compared with those of 9 healthy volunteers (HVs).

RESULTS

The threshold for pain, but not that for first sensation and urge to defecate, was significantly decreased in IBS patients (6 +/- 1 mm Hg) compared with FAP patients and HVs (17 +/- 1 and 22 +/- 2 mm Hg, respectively). In HVs and patients with FAP, ingestion of a meal induced a decrease in rectal volume with an early and late component. This motor pattern was absent in children with IBS. In IBS patients, no rapid volume waves were observed during fasting in contrast to FAP patients (2.7 +/- 0.3/10 min) and HVs (1.8 +/- 0.5/10 min).

CONCLUSIONS

Children fulfilling the Rome II criteria for IBS have a significantly lowered threshold for pain and a disturbed contractile response to a meal. Comparable to results reported in adults, sensory and motor abnormalities might play a pathophysiologic role in childhood IBS.