Transabdominal ultrasound measurement of rectal diameter is dependent on time to defecation in constipated children

Assessing fecal load with ultrasound in children with colorectal pathology: ReKiSo study

PURPOSE

To evaluate bowel management for children with colorectal pathology by measuring transverse rectal diameter (TRD) and assessing fecal load with transabdominal rectal ultrasound (TRU).

METHODS

Prospective case-control study of children receiving bowel management (BM) between 04/2023 and 04/2024 was done. There was inclusion of patients with Hirschsprung disease (HD), anorectal malformation (ARM) and functional constipation (FC). Patients with other congenital or neurological conditions were excluded. Control group consisted of inpatients and outpatients without abdominal complaints. FC was diagnosed according to ROM-IV-criteria. For HD and ARM, we followed a list of symptoms. To assess fecal load, we visualized the TRD using the Klijn (Klijn et al. in J Urol 172:1986-1988, 2004) method. The bladder was moderately full. The fecal load was assessed retrograde from the rectum. Follow-up was at 1/3/6 months. Secondary data were collected from medical records. Sample size calculated a priori and follow-up group with new gathered data.

RESULTS

p value for TRD in all groups significant with p < 0.05 and in grouped follow-up.

CONCLUSION

Ultrasound is a useful tool for assessing fecal load and helps diagnose constipation and monitor BM. Irrespective of colorectal pathology, a cut-off of 3 cm seems to discriminate between children without constipation/overload symptoms and asymptomatic patients. We present a radiation-free method for monitoring bowel management.

Testing in functional constipation-What's new and what works

BACKGROUND

Constipation is among the most common symptoms prompting a consultation with a paediatric gastroenterologist. While most patients will respond to lifestyle and dietary changes and conventional therapy, some may require diagnostic studies.

AIM

To review the diagnostics studies used to evaluate children with functional constipation.

MATERIALS AND METHODS

There is no evidence to support the routine use of abdominal X-rays in the evaluation of paediatric constipation. Colon transit by radiopaque markers (ROM) should be indicated when medical history does not match clinical findings, to guide colon manometry (CM) performance and to discriminate between faecal incontinence from functional constipation and non-retentive faecal incontinence. Colon scintigraphy may be useful as an alternative to ROM. Lumbar spine MRI may be indicated to evaluate for spinal abnormalities. The role of defecography has not been properly evaluated in children. Anorectal manometry in children is indicated primarily to evaluate anal resting pressure, presence and quality of the recto-anal inhibitory reflex and simulated defecation manoeuvres. The CM is indicated to guide surgical interventions after failing medical therapy.

CONCLUSIONS

The goal of these studies is to identify treatable causes of constipation. Most of these studies are designed to evaluate anatomy, transit and/or colon/rectum motility function and are primarily indicated in those who fail to respond to conventional therapy.

Meta-analysis: Intestinal ultrasound to evaluate colonic contents and constipation

BACKGROUND

Constipation can be diagnosed clinically using the Rome criteria. Ultrasound (US), which lacks the radiation exposure of conventional X-ray, holds promise as a non-invasive tool to evaluate colonic contents and constipation.

AIM

To examine the role of US in the assessment of constipation.

METHODS

We performed a systematic search of Embase (OVID, 1984), Medline (Ovid, 1946), Cochrane Central, ClinicalTrials.gov and Australia New Zealand Clinical Trials Registry from database inception to 26 January 2024 according to PRISMA guidelines and prospectively registered with PROSPERO. All studies using US to assess constipation or colonic contents in either adults or children were included. Rectal diameter measurements were pooled in meta-analysis. Risk of bias was assessed using the Newcastle Ottawa Scales and Joanna Briggs Institute checklists.

RESULTS

Of 12,232 studies screened, 51 articles (6084 patients; 3422 children) describing US to assess symptoms in patients with constipation were included. Most studies used Rome criteria to diagnose constipation. Rectal diameter was associated with clinical constipation in 29 paediatric studies (3331 patients). Meta-analysis showed the mean rectal diameter of constipated patients was significantly higher than controls (mean difference 12 mm, 95% confidence intervals (CI): 6.48, 17.93, p < 0.0001, n = 16 studies). Other features of constipation on US included posterior acoustic shadowing and echogenicity of luminal contents.

CONCLUSION

US is an appealing imaging modality to assess luminal contents and constipation. Further well-designed studies are required to validate US metrics that accurately identify constipation.

Imaging in pediatric disorders of the gut-brain interactions: current best practice and future directions

INTRODUCTION

Disorders of Gut-Brain Interactions (DGBI) are a common clinical problem in children and pose significant challenges to the attending pediatrician. Radiological investigations are commonly ordered to evaluate these children.

AREA COVERED

This review focuses on the current best practice of using radiological investigations in DGBIs and how novel radiological investigations could revolutionize the assessment and therapeutic approach of DGBI in children.

EXPERT OPINION

We believe imaging in DGBI is still in its early stages, but it has the potential to revolutionize how we diagnose and treat children with DGBI. As the understanding of the gut-brain axis continues to grow, we can expect to see the disappearance of conventional imaging techniques and the emergence of more sophisticated imaging techniques with less radiation exposure in the future which provide more clinically meaningful information regarding the gut-brain axis and its influence on intestinal function. Some of the novel imaging modalities will be able to broaden our horizon of understanding DGBI in children providing more useful therapeutic options to minimize their suffering.

Transabdominal ultrasound of rectal diameter in healthy infants: a prospective cohort study during the first year of life

AIM

Transabdominal rectal ultrasound (TRU) is used to measure transverse rectal diameter (TRD) in order to diagnose functional constipation (FC) and megarectum, and to evaluate treatment. The proposed cut-off value is 3.0 cm. Currently, no standardised values exist for children below the age of 4. We used repeated TRUs to establish reference TRD values in healthy infants and to describe rectal diameter in infants with FC.

METHODS

This prospective observational cohort study enrolled healthy term babies from a maternity department. TRD measurements were taken at 2 and 12 months of age, and questionnaires completed in interviews helped diagnose FC according to Rome III criteria.

RESULTS

Two hundred TRUs were performed on 110 infants (62 males). In infants without FC anytime, the mean TRD at 2 months was 1.56 (SD 0.32) cm and at 12 months 1.78 (0.47) cm, while the 95th percentiles were 2.26 and 2.64 cm, respectively. In 77 infants with two TRUs, the mean increase was 0.21 cm (95% confidence interval: 0.099-0.318). Thirteen infants were diagnosed with FC during the study period. At 2 and 12 months of age, there was no difference in TRD between infants with and without FC.

CONCLUSION

TRD increased from 2 to 12 months. We suggest 2.3 cm as an upper limit for normal TRD at 2 months and 2.6 cm at 12 months. Infants diagnosed with FC did not have a greater TRD than infants without, either before or after treatment. Further studies are needed to evaluate the usefulness of TRU in infants with FC or megarectum.

Rectal measurements and their correlation with bowel habits: Evaluation by trans-abdominal ultrasound in children with functional constipation

AIM

Constipation is one of the most common complaints in childhood affecting the quality of life of both children and parents. This study intends to investigate rectal measurements on ultrasound and their relationship with bowel habits.

METHODS

In this cross-sectional study, 100 children with functional constipation (FC) referred to a single hospital between 2018 and 2019 were enrolled. After obtaining informed consent, a questionnaire including demographic and constipation characteristics was completed, and a physical examination including digital rectal examination (DRE) was performed. Complete abdominopelvic ultrasound was then performed. Target measurements included rectal transverse diameter (RTD), rectal anterior wall thickness (RAWT) and the presence of faecal impaction.

RESULTS

One hundred children with a mean age of 7.68 ± 3.30 years were present in the study. The mean duration of constipation was 15.86 ± 13.34 months. In 14% of children, painful defaecation was reported. 88% of children had some degree of faecal incontinence. According to the ultrasound findings, the mean RTD and RAWT were 3.39 ± 0.73 cm and 2.77 ± 0.68 mm, respectively, and faecal impaction was present in 70% of cases. There was a positive correlation between RTD and RAWT with age, duration of constipation and the presence of hard stools, and there was a negative correlation with frequency of defecation (P < 0.05).

CONCLUSION

RTD and RAWT increased with increasing constipation duration and the presence of hard stools and decreased with increasing frequency of defaecation. DRE could be omitted from the initial clinical assessment if you had access to reliable ultrasound data.

Rectum sizes: Assessment by ultrasonography in children with functional constipation

AIM

This study aimed to compare the transverse diameter and thickness of the anterior wall of the rectum in children with normal bowel movement and children with functional constipation in different age groups. Another objective was to find correlations of rectum sizes with faecal incontinence and constipation duration.

METHODS

In the study, we included children with normal bowel movement and functional constipation diagnosed based on the Rome III and Rome IV criteria. We collected clinical data from the parents. We measured the rectum transverse diameter and the thickness of the anterior wall by abdominal ultrasound.

RESULTS

The study included 65 children, 31 with normal bowel movement and 34 with functional constipation. The rectum transverse diameter and the thickness of the anterior wall had statistically significant higher values in patients with constipation (P < 0.05). There was a moderate and significant correlation between the duration of the disease (mean ± standard deviation = 31.7 ± 33.1 months) and rectum transverse diameter (r = 0.54; P = 0.0009). The rectum transverse diameter correlated moderately with the presence of faecal incontinence (r = 0.62; P = 0.003), but the thickness of the anterior wall did not correlate with this symptom (r = 0.02; P = 0.39).

CONCLUSIONS

We found statistically significant differences between the transverse rectal diameter and thickness of the rectum anterior wall, measured by abdominal ultrasound, in children with functional constipation compared with normal defaecation patterns. Faecal incontinence and long-term constipation were correlated with the increased rectum diameter.

Changes in the parameters of the rectoanal inhibitory reflex in children with functional constipation and large rectum

BACKGROUND

Abdominal ultrasound and anorectal manometry are part of the investigations used to assess children with functional constipation. This study aimed at assessing the changes in the characteristics of the rectoanal inhibitory reflex (RAIR) in children with functional constipation and correlating them with the dimensions of the rectum, measured by abdominal ultrasound. A secondary objective was to compare the rectum size in children with and without constipation.

METHOD

We retrospectively reviewed the clinical data and investigations results of 51 children (mean age±standard deviation (SD) = 5.8±3.5 years) with functional constipation who came to our clinic between January 2013 and February 2020. The assessment of these patients included both the assessment of the transverse diameter of the rectal ampulla by abdominal ultrasound and anorectal manometry. The studied parameters of RAIR were: the minimal volume of air necessary to induce RAIR, in all the patients with functional constipation, and in 20 of them, relaxation time, latency and relaxation percentage. A control group was formed of 27 children (mean age±SD = 5.1±4 years) without digestive diseases and with normal intestinal transit, who were assessed by abdominal ultrasound.

RESULTS

The mean value ±SD of the volume of air necessary to induce RAIR was 21.9±12.1 cm3 air. There was no correlation between the rectum transverse diameter and the minimal air volume that triggered RAIR (r=-0.01, p=0.94). The mean value ±SD of the transverse diameter of the rectum in patients with functional constipation was 39±14 mm, and in children without constipation 26±6 mm (p<0.05). The mean duration of the symptoms in children with functional constipation was 2.8 years.

CONCLUSIONS

There were no correlations between the volume of air that induced the RAIR and the transverse diameter of the rectum in children with functional constipation. The transverse diameter of the rectum was increased in children with long-term functional constipation.

Emergency Provider Use of Plain Radiographs in the Evaluation of Pediatric Constipation

BACKGROUND

More than half of children evaluated as outpatients for abdominal pain are diagnosed with constipation. X-ray use in this scenario is variable: less than 5% in clinic settings, greater than 70% in emergency departments. X-rays increase misdiagnosis rate, remain costly, and involve radiation exposure.

OBJECTIVES

The aim of this study was to assess the use of plain radiographs by pediatric emergency medicine (PEM) providers in the diagnostic evaluation and management of pediatric constipation.

METHODS

A cross-sectional survey of PEM providers was performed. Survey participants were subscribers to the American Academy of Pediatrics Section on Emergency Medicine Listserv. To assess diagnostic and therapeutic approaches, participants were presented a case of pediatric constipation meeting Rome III clinical criteria. Participants also categorized frequency of x-ray use, reasons for obtaining, estimated diagnostic utility, and elements of institutional standard approach. Descriptive statistical analyses were performed.

RESULTS

Three hundred five of 1272 Listserv members (24%) responded. Ninety-nine percent elected to treat for constipation in a case meeting Rome III clinical criteria; one third (31%) would obtain plain radiographs for this same scenario. Plain radiographs were viewed as somewhat (59%) or minimally (29%) value-added in the evaluation of suspected pediatric constipation. Obtaining family buy-in (44%) was the most common reason for utilizing plain radiographs. Frequency of use varied across geographic regions and with participant and hospital characteristics.

CONCLUSIONS

This survey suggests that many PEM providers obtain radiographs to convince families of the diagnosis of constipation. This is not a viable management plan given the risks of radiation as well as costs. There remains room for improvement as we attempt to reduce use of radiation in the evaluation of common pediatric illnesses.

ULTRASONOGRAPHY IN DETERMINING THE RECTAL DIAMETER AND RECTAL WALL THICKNESS IN CHILDREN WITH AND WITHOUT CONSTIPATION: A CASE-CONTROL STUDY

ABSTRACT BACKGROUND: Ultrasonography has shown to be useful in the diagnosis of constipation. OBJECTIVE: The aim of this study was to compare the rectal diameter and rectal wall thickness in children with and without constipation. METHODS: Children with the diagnosis of constipation according to Rome III criteria were included in the study. The children underwent transabdominal sonography for the evaluation of rectal diameter and rectal wall thickness. Ultrasonography was performed with a full bladder. Children without constipation who underwent abdominal sonography were assigned to the control group. RESULTS: The rectal diameter was larger in children with constipation than in children without constipation (31.72±9.63 mm vs 19.85±4.37 mm; P=0.001). The rectal wall was thinner in children with constipation than in children without constipation (1.75±0.33 mm vs 1.90±0.22 mm; P=0.032). There was no significant difference between boys and girls with constipation in terms of rectal diameter (31.02±8.57 mm 32.77±11.35 mm; P=0.63). CONCLUSION: Transabdominal rectal diameter measurement may be useful in the diagnosis of constipation.

Functional constipation in children: challenges and solutions

This review intends to update what is known about and what is still a challenge in functional constipation (FC) in children regarding epidemiology, pathophysiology, diagnosis, and management. Although FC is a common childhood problem, its global burden remains unknown as data from parts of the world are missing. Another problem is that there is a large variation in prevalence due to differences in study methods and defining age groups. The pathophysiology of FC remains unclear to date but is probably multifactorial. Withholding behavior is likely to be the most important factor in toddlers and young children. Genetics may also play a role since many patients have positive family history, but mutations in genes associated with FC have not been found. Over the past years, different diagnostic criteria for FC in infants and children have been proposed. This year, Rome IV criteria have been released. Compared to Rome III, it eliminates two diagnostic criteria in children under the age of 4 who still wear diapers. Physical examination and taking a thorough medical history are recommended, but other investigations such as abdominal radiography, transabdominal recto-ultrasonography, colonic transit time, rectal biopsies, and colon manometry are not routinely recommended. Regarding treatment, guidelines recommend disimpaction and maintenance therapy with polyethylene glycol (PEG) with or without electrolytes. But experience shows that acceptability, adherence, and tolerance to PEG are still a challenge. Counseling of parents and children about causes of FC is often neglected. Recent studies suggest that behavior therapy added to laxative therapy improves the relief of symptoms. Further homogeneous studies, better-defined outcomes, and studies conducted in primary care are needed.