| Klijn et al. The diameter of the rectum on ultrasonography as a diagnostic tool for constipation in children with dysfunctional voiding. 2004. Journal of Urology 172[5 Pt 1], 1986-1988 | Study type:
Diagnostic. Case control
Evidence level:
III
Study aim:
to prove the accuracy of the transverse diameter of the rectum on ultrasonography as an additional parameter for diagnosing constipation in children with lower urinary tract dysfunction | 49 patients
Inclusion criteria:
Positive diagnosis of constipation, made by patient history and physical examination when the patient had at least 2 positive signs, including:
- -
2 or fewer bowel movements weekly without laxative therapy - -
2 or more episodes of faecal soiling weekly - -
periodic passage of a large amount of stool once every 7 to 30 days - -
palpable abdominal and/or rectal mass
Exclusion criteria:
laxative therapy, constipation due to neurological disease, disease of the gastrointestinal tract based on endocrinological, metabolic, genetic or toxic disease, or connective tissue disease
Setting:
hospital | 49 patients
aged between 5-13 years
Group 1:
23 patient s with positive history of voiding dysfunction and constipation
Group 2:
26 urological patients without lower urinary tract dysfunction and a normal defecation pattern, diagnosed with undescended testicle, periodic control for upper urinary tract dilatation, etc.
Country:
UK | Test:
lower abdominal ultrasound of rectum
Reference Standard:
None reported | Rectal diameter (cm)
(Mean, standard deviation, 95% CI)
- -
Group 1 (constipated, n=23): 4.9 (1.01; 4.4 to 5.3) - -
Group 2 (control, n=26) 2.1 (0.64; 1.8 to 2.4)
p<0.001 | Ultrasound done with the patient supine. 7.5 MHz probe applied on abdominal skin approximately 2cm above the symphysis. Measurement performed with moderate (30-70 % capacity of for age) filled bladder at an angle of about 15 degrees downward from the transverse plane. The diameter of the rectum, behind the bladder was measured twice.
If stools had been passed in the last two hours or patients had an urge to defecate during the investigation the were not included in the study, but this situation did not occur
In all patients it was possible to obtain a reliable and repeatable measurement of the rectum if at least some bladder filling was present
It was not reported who performed the ultrasound, or whether this person was blinded
No significant difference in age between the two groups (p=0.20) or in period between the last time a stool was passed prior to the rectal measurement (p=0.16)
In all patients with voiding dysfunction and faecal constipation (Group 1) rectal examination confirmed stool in the rectum, but there are no data reported on this variable for the control group, probably for ethical reasons
Source of funding: Not stated |
| Singh et al. Use of pelvic ultrasound in the diagnosis of megarectum in children with constipation. 2005. Journal of Pediatric Surgery 40[12], 1941-1944 | Study type:
Diagnostic. Case control
Evidence level:
III
Study aim:
to establish normal values for the rectal crescent in healthy children, compare them with the rectal crescent in children with constipation and explore whether pelvic ultrasound can hep in establishing a diagnosis of megarectum | 177 children
Inclusion criteria:
Children referred after failing to respond to medical treatment. Diagnosis of constipation made once the child had 2 or more of the following:
- -
less than 3 bowel movements/week - -
periodic passage of a large stool with discomfort or pain - -
a palpable abdominal mass on physical examination - -
faecal soiling in the presence of any of the above
Exclusion criteria:
Previous anorectal surgery (e.g. pull-through procedures for Hirschsprung's disease or anorectal myectomy)
Setting:
tertiary referral centre | 177 children
Group 1:
82 children (median age 5.5 years, range 0.30-15.30) with no history of constipation or other anorectal or gastrointestinal problems and no previous anorectal surgery
Group 2:
95 children (median age 6.5 years, range 0.40-16.40) with a history of constipation of at least 6 months duration, referred to a tertiary referral centre
Country:
UK | Test:
Pelvic ultrasound
Reference test:
none reported | Median rectal crescent (cm)
Group 1 (healthy children):
2.4 (range 1.3 to 4.2; IQR 0.72)
Group 2 (children with constipation):
3.4 (range 2.10 to 7.0; IQR 1.0)
p<0.001
IQR= interquartile range
Receiver operating characteristic analysis:
- -
Area under the curve: 0.847 95% CI: 0.791 to 0.904
Cut-off point for establishing the diagnosis of megarectum:
3.0 cm | A portable US machine with a 5-MHz probe (falcon 2101 Ultrasound scanner with a transducer type 8803 [3.0-5.0 MHz], B-K Medical, Copenhagen, Denmark) was used.
The same individual performed all the US scans, but not other data on this were reported (as blinding, individual's experience in radiology, etc)
All children had a full or partially full bladder at the time of measurement. In cases where the child was initially scanned and the bladder was noted to be empty, the US was abandoned and the child was offered liberal fluids orally. The scan was repeated within an hour and in all cases, by then, the child had a full or partially full bladder
The US probe was applied on the anterior abdominal wall in the midline, approximately 1-2 cm above the symphysis at a 90 degrees angle to the abdominal wall. This showed the impression of the rectum behind the urinary bladder as a crescent which was measured in centimetres
There were no significant differences between the two groups in terms of age, weight and height (p values 0.114, 0.198 and 0.131 respectively)
Results were adjusted for confounders (age, height and weight)
Age and rectal diameter were significantly related (p<0.0001): the older the child the bigger the rectal diameter
Time to last evacuation was not ascertained and authors acknowledged this may influence the size of the rectal crescent
Source of funding: not stated |
| Bijos et al. The usefulness of ultrasound examination of the bowel as a method of assessment of functional chronic constipation in children. 2007. Pediatric Radiology 37[12], 1247-1252 | Study type:
Diagnostic Case control
Evidence level:
III
Study aim:
to determine whether a new method of ultrasound (US) assessment of stool retention could be used as a method of identifying children with functional chronic constipation, and to determine whether children with an enlarged rectum and colon (as seen on US) should be referred for further procedures such as proctoscopy and assessment of colonic transit time. | 225 children
Inclusion criteria:
Referred because of chronic constipation, based on history and physical examination: defecation disorders persisting longer than 6 months, all patients fulfilled Rome II criteria for defecation disorders (frequency of bowel movements less than twice a week, consistency and size of stool caused pain during defecation, withholding behaviour)
Exclusion criteria:
anatomic abnormality (Hirschsprung's disease, congenital abnormalities of the anorectal region) neurological and psychiatric conditions (cerebral palsy, spina bifida, mental retardation, anorexia nervosa), metabolic conditions (diabetes mellitus/insipidus) endocrine disorders (hypothyroidism), previous thoracic or abdominal surgery
(control patients: normal defecation patterns, treated for various symptoms like chronic abdominal pain, food allergies)
Setting:
gastroenterology outpatient clinic | 225 children
Group 1:
120 children with chronic constipation (72 boys, mean age 6.25 years, range 1.6 to 17.9)
Group 2:
105 children with normal defecation pattern (mean age 8.25 years)
Country:
Poland | Test:
Abdominal ultrasound
Reference tests:
Proctoscopy (for diagnosing faecal impaction)
Transit times (hours, upper limit of 66 based on literature)
≤66: normal-transit constipation
66-100: slow-transit constipation
>100: very delayed slow-transit constipation | Diameters of rectal ampulla by US (mm, mean ± SD) Age (years)
- -
Group 1 (constipated): All ages: 43. 06 ± 9.68 (range 30 to 82) ≤3: 38.35 ± 8.65 3.1 to 6: 41.16 ± 8.72 6.1 to 12: 46.15 ± 9.56 >12 years: 49.09 ± 10.19
- -
Group 2 (control): All ages: 31. 83 ± 8.24 (range not given) ≤3: 27.07 ± 8.00 3.1 to 6: 29.25 ± 6.86 6.1 to 12: 32.85 ± 8.73 >12 years: 35.15 ± 7.18
p<0.001 for every age group
Mean rectopelvic ratios for all ages (mean ± SD) (Cut-off value to diagnose megarectum: 0.189)
- -
Group 1 (constipated): All ages: 0.22 ± 0.05 ≤3: 0.24 ± 0.060 3.1 to 6: 0.23 ± 0.05 6.1 to 12: 0.22 ± 0.05 >12 years: 0.19 ± 0.04
- -
Group 2 (control): All ages: 0.15 ± 0.04 ≤3: 0.17 ± 0.05 3.1 to 6: 0.16 ± 0.04 1 to 12: 0.15 ± 0.05 >12 years: 0.14 ± 0.03
p<0.001 for age groups (years): ≤3;
3.1 to 6; 6.1 to 12
p=0.002 for >12 years
US vs. proctoscopy in the diagnosis of faecal impaction
- -
Sensitivity: 88.3%
Mean colonic transit times:
Children with faecal impaction (as per US) had significantly longer average segmental transit time for the rectum, sigmoid and left colon (p<0.001, p=0.0015 and p=0.0104 respectively) there was not statistically significant difference for the right side of the colon. Children with an overfilled splenic flexure on US had a significantly longer transit time in the left side of the colon (p=0.0029)
Definitions of:
- -
Faecal impaction (as per US in sagital plane): when pelvic structures were covered by stool masses and were not even partially visible. - -
Overfilled colon (as per US): Overfilled bowel at the splenic flexure: when it was impossible to visualise the entire length of the left kidney due to the lack of visibility of the lower pole of the kidney because of bowel contents. Probe applied to the long axis of the spleen. Overfilling of the transverse colon: when the superior mesenteric artery was not visible with the probe applied in the sagital plane over the aorta
| US assessment of stool retention and colonic enlargement involved measurement of the transverse diameter of the rectal ampulla (by US) and pelvic width (externally using a measuring tape) Pelvic width was defined as the distance between the external margins of the anterior superior iliac spines. The ratio between the transverse diameter of the rectal ampulla and transverse diameter of the pelvis was calculated to give the rectopelvic ratio.
US was performed using a Philips HDI 4000 US unit (Philips, Best, The Netherlands) equipped with three electronic transducers with various frequencies from 2-14 MHz. children were examined before food and had a slightly filled bladder. Patients who passed stool on the day of the examination were temporarily excluded from the study until they became constipated again.
Rectal ampulla width was measured with the probe applied to the anterior abdomen above the symphysis. Measurement was performed on oblique transaxial scanning plane to obtain transverse diameter of the ampulla. Measurement was taken several times and the highest one recorded taken as the final measurement
Total and segmental colonic transit time measured by the modified sixth day Hinton method. Total and segmental time obtained by multiplying the number of radiopaque markers seen on the radiograph by 1.2 (time in hours/number of markers swallowed by the patient)
The same individual performed all the US scans, but not other data on this were reported (as blinding, individual's experience in radiology, etc)
It is not clear what number of children underwent each of the tests
It is not clear how the authors calculated the sensitivity of the US vs., proctoscopy to diagnose faecal impaction, as the results of proctoscopy are not reported
It is difficult to know exactly how many children were diagnosed with faecal impaction by US, as these data are reported only in the form of a bar graph. Data on number of children diagnosed with “overfilled colon” are not reported at all.
It is not clear whether “enlarged” and “overfilled” colon mean the same for the authors, as no measurements of “enlarged” colon are reported.
Children apparently underwent DRE but no results are reported
Control group did not differ from patients regarding gender, the comparison regarding age is not clearly reported
Source of funding: Not stated |
| Joensson et al. Transabdominal ultrasound of rectum as a diagnostic tool in childhood constipation. 2008. Journal of Urology 179[5], 1997-2002 | Study type:
Diagnostic. Case control
Evidence level:
III
Study aim:
To look into a possible correlation between a dilated rectum measured by ultrasound and a faecal mass detected by digital rectal examination. To evaluate whether this method could diagnose constipation according to Rome III criteria | 51 children
Inclusion:
Children referred to outpatient clinic with either constipation or faecal incontinence, with or without urinary incontinence and a history of UTI. Patients fulfilled Rome III criteria, had at least 2 of the following characteristics:
- -
fewer than 3 bowel movements/week - -
more than 1 episode of faecal incontinence weekly - -
large stools in rectum by DRE or palpable on abdominal palpation - -
occasional passage of large stools - -
display of retentive posturing and withholding behaviour painful defecation
(healthy control children were recruited form employees of the Paediatrics Department at the hospital)
Exclusion criteria:
known organic causes of constipation, including Hirschsprung's disease, spinal and anal congenital abnormalities, previous surgery on the colon, inflammatory bowel disease, allergy, metabolic and endocrine diseases, children receiving drugs know to affect bowel function during a 2-mont period before initiation (not specified which)
Setting:
outpatient clinic | 51 children, aged 4-12 years
Group 1:
27 children (mean age 7.0±1.8 years) diagnosed with chronic constipation by Rome III criteria
Group 2:
24 healthy children (mean age 9.1±2.7 years)
Country:
the Netherlands | Test:
Transabdominal ultrasound of rectum
Reference test:
Digital rectal examination (DRE) | Rectal diameter (mm) (mean ± 2SD)
- -
Children with rectal impaction as per DRE (n=22, 20 constipated, 2 healthy): 40.5 ± 7.9 - -
Children without rectal impaction as per DRE (n=26, 7 constipated, 19 healthy): 21.0 ± 4.2
p<0.001
Cut-off value for the presence of rectal impaction (average rectal diameter of children without impaction plus 2SD):
29.4 mm
Rectal diameter (mm) (mean ± 2SD)
Before treatment:
- -
Group 1 (Constipated, n=27): 39.6 ± 8.2 - -
Group 2 (Healthy): 21.4 ± 6.00
p<0.001
After treatment
- -
Group 1 (Constipated, responded to treatment, n=15): 26.9 ± 5.6
p<0.01 (as compared to same group before)
p<0.05 (as compared to group 2)
11 children did not respond to treatment and no significant differences were observed in their rectal diameter as compared to pre-treatment
Intraobserver variability:
- -
coefficient of variation of the 3 consecutive measurements: 5.8% ± 4.3%
7 of the constipated children (26%) had a rectal diameter smaller than the established cut-off point for rectal impaction, despite the fact that they fulfilled the Rome III criteria for constipation. 2 healthy children with rectal impaction had a markedly larger rectal diameter (38 and 31 mm) than the other healthy controls. | For transabdominal measurements of rectal diameter: a 7.5 MHz probe applied to the abdomen approximately 2cm above the symphysis at 10 to 15-degree downward angle. Diameter of the rectum measured in traverse plane. At each session (n=3) diameters were measured three times and mean value was calculated. All children had a partially full bladder range (28 to 450 ml) corresponding to 20-155% of expected bladder capacity for age at the time of the measurement. In case of empty bladder fluid was offered orally and scanning was repeated. If the child had a bowel movement within 3 hours before the investigation or had an urge to defecate, the result was excluded. All investigations were performed by the same observer (a paediatric intern, who had no prior radiological experience) This observer was not reported blinded to the study objectives and patient's characteristics
There was no significant difference in height and weight distribution between the 2 groups, but the healthy children were significantly older than the constipated children
Constipated children received 3 days of disimpaction followed by 4 weeks of laxative treatment with polyethylene glycol and behavioural therapy. No other details reported
No significant correlation between bladder volume at the time of measurement and rectal diameter (r=0.04)
There are missing data not accounted for
Apparently healthy children diagnosed with faecal impaction did not receive any laxative treatment, which is worrying from an ethical point of view
Authors acknowledged the abdominal ultrasound technique might bear technical limitations related to artefacts like: acoustic enhancement, speed error, and refraction artefacts although their possible influence on their results is unclear
No correlation was found between the rectal diameter and age or sex of the children in either group
Source of funding: Supported by Karen Elise Jensen Foundation |
| Lakshminarayanan et al. A new ultrasound scoring system for assessing the severity of constipation in children. 2008. Pediatric Surgery International 24[12], 1379-1384 | Study type:
Diagnostic prospective case series
Evidence level:
III
Study aim:
To assess the correlation between severity of constipation and ultrasound (US) findings, the correlation between clinical examination and US findings and the correlation between findings at serial outpatient follow-up visits to assess clinical improvements and US findings | 500 children
Inclusion:
All children, both new referrals and follow-up, attending a constipation outpatient clinic
Exclusion criteria:
Children not compliant to have assessment done by US, cases when the US machine was not available
Setting:
Constipation outpatient clinic | 500 children
317 male
median age: 8 years (age range 8 months to 18 years)
Country:
UK | Test:
Pelvic ultrasound
Both transverse and longitudinal planes
All scans done by same clinician after very brief training
Reference test:
Clinical assessment:
Standard symptoms severity scoring sheet (SSS), completed by parent or child if old enough
Clinical assessment done by detailed history taking and abdominal examination | Correlation between SSS and US score
- -
first visit (n=500) Mean SSS: 23.5 (SD 11.6) Mean US total score: 4.02 (SD 2.8) Pearson's correlation: 0.39 P<0.001 - -
second visit (n=226) Mean SSS: 19.9 (SD 12.6) Mean US total score: 3.49 (SD 2.6) Pearson's correlation: 0.49 P<0.001 - -
third visit (n=62) Mean SSS: 23.02 (SD 13.7) Mean US total score: 3.66 (SD 2.6) Pearson's correlation: 0.26 P=0.04 - -
fourth visit (n=12) Mean SSS: 28.5 (SD 16.8) Mean US total score: 4.9 (SD 3.2) Pearson's correlation: 0.70 P=0.01
Pearson's correlation between US score and clinical examination of palpable faeces per abdomen
- -
first visit (n=500) Mean palpable faeces score: 1.42 (SD 1.6) Mean US total score: 4.02 (SD 2.8) Pearson's correlation: 0.89 P<0.001 - -
second visit (n=226) Mean palpable faeces score: 1.10 (SD 1.6) Mean US total score: 3.49 (SD 2.6) Pearson's correlation: 0.845 P<0.001 - -
third visit (n=62) Mean palpable faeces score: 1.10 (SD 1.6) Mean US total score: 3.66 (SD 2.6) Pearson's correlation: 0.77 P<0.001 - -
fourth visit (n=12) Mean palpable faeces score: 1.92 (SD 1.7) Mean US total score: 4.9 (3.2) Pearson's correlation: 0.91 P<0.001
| Additional information from study
- -
US scoring sheet (this score can be used even with an empty bladder)
Stool height (x): (bladder effect (y)):
No stool: 1 (empty bladder: 0
Retro bladder: 2 (n compression: 0)
Just above bladder: 3
Nearly umbilicus: 4 (indented bladder: 1)
To umbilicus: 5 (Flattened bladder: 2)
Beyond umbilicus: 6 (displaced bladder: 3)
Can't see upper edge: 7
Uncooperative: 99
Not available: 0
total =x+y
- -
Symptom severity scoring sheet: Filled in by parent, or child if old enough. Q1 About the soiling problem (faecal incontinence/mess in underclothes): - -
none (0) - -
rarely (1) - -
occasionally (2) - -
only is bowel loaded (5) - -
continuous day only (8) - -
continuous day and night (10)
Q2 About the delay from passing one complete stool to the next: - -
daily stool (0) - -
every 2 or 3 days (1) - -
every 3-5 days (2) - -
every 5-10 days (5), - -
greater than 10 (8) - -
never (10)
Q3 About pain and difficulty with passing stools: - -
none (0) - -
occasionally (1) - -
often (2) - -
with most stools (4) - -
with every stool (5)
Q4 About the amount and types of medicine needed regularly over the last month: - -
none (0) - -
softeners only e.g.: lactulose or Docusate or daily Movicol or methyl cellulose (1) - -
softeners and daily stimulants e.g.: Senokot or picosulfate (2) - -
softeners and daily stimulants and weekend extra picosulfate or Movicol (4) - -
medicines as well as extra weekend klenprep or high dose Movicol (8) - -
medicines as well as regular enemas or suppositories (10)
Q5 About how your child's general health has been affected by the bowel problem over the last month: - -
well (0) - -
occasionally ill (2) - -
often ill (3) - -
ill most days (4) - -
never well (5)
Q6 About behaviour related to the bowel problem: - -
cooperative OK (0) - -
needs reminding to use the lavatory/pot (2) - -
refuses the lavatory or pot (3) - -
also refuses medicines (4) - -
also generally difficult behaviour (5)
Q7 overall, which best describes how the problems are now compared with the last time seen at hospital: - -
nearly completely OK (0) - -
much better (1) - -
some improvement (4) - -
still as difficult (8) - -
getting worse (12)
Filled in by practitioner Amount of stool detected on clinical examination of abdomen score: - -
None palpable: 0 - -
Little: 1 - -
Suprapubic only: 2 - -
To umbilicus: 3 - -
Beyond umbilicus: 5 - -
Reaching ribs: 8
Reviewers comments
No control/comparison group
Very small sample size at the fourth visit
Source of funding: Not stated |
