Chronic constipation: no longer stuck! characterization of colonic dysmotility as a new disorder in children ¹

The gastrointestinal transit of markers in pigs has been well studied, but the methods and approaches are different from gastrointestinal studies performed in humans clinically.

To develop a non-invasive method of estimating oral-rectal transit times in young pigs.

We performed transit studies in 3 groups of 4 week-old, Large White female pigs. Group 1. Ten animals (5.7±0.34 kg (mean±SEM)) were fed blue-dyed grower feed and placed under video surveillance. Group 2a. Twenty-two animals (7.7±0.59 kg) from the same pig supplier were administered 18 4 mm-diameter radio-opaque plastic markers under light anaesthesia (5% isofluorane), and we took abdominal x-rays at 6, 30, 54 and 78 h. Group 2b. Eight pigs (9.2±0.48 kg) from a different supplier also underwent plastic marker transit studies.

Using blue dye (fluid transit), the median (25th, 75th percentiles) time to first incidence of blue-dyed stool was 13.2 (10.2, 18.1) h and to last blue stool was 24.1 (22.4, 40.3) h. Using plastic markers, markers were evacuated between 30 and 80+ hours with differences in stomach emptying between two groups of animals from different farms. Median oral-rectal transit times were 25.2 (17.8, 40.5) h and 48.9 (26.9, 68.3) h in the second and third groups (M-W test, P=0.04).

There are differences in the transit of fluid- and solid-phase marker in pigs. Fluid-phase markers appear earlier than solid markers. Monitoring the evacuation of fluid-phase dye using video surveillance is difficult. Using plastic markers and x-rays to estimate the segmental and oral-rectal transit times in young pigs may be a useful method that can be correlated to oral-rectal transit studies performed in humans. The ability of pigs to hold solids in the stomach for extended times complicates transit studies. There are some differences in transit in pigs from different breeders.

In slow-transit constipation (STC) pancolonic manometry shows significantly reduced antegrade propagating sequences (PS) and no response to physiological stimuli. This study aimed to determine whether transcutaneous electrical stimulation using interferential current (IFC) applied to the abdomen increased colonic PS in STC children.

Eight children (8–18 years) with confirmed STC had 24-h colonic manometry using a water-perfused, 8-channel catheter with 7.5 cm sidehole distance introduced via appendix stomas. They then received 12 sessions (20 min/3 × per week) of IFC stimulation (2 paraspinal and 2 abdominal electrodes), applied at a comfortable intensity (< 40 mA, carrier frequency 4 kHz, varying beat frequency 80–150 Hz). Colonic manometry was repeated 2 (n = 6) and 7 (n = 2) months after IFC.

IFC significantly increased frequency of total PS/24 h (mean ± SEM, pre 78 ± 34 vs post 210 ± 62, p = 0.008, n = 7), antegrade PS/24 h (43 ± 16 vs 112 ± 20, p = 0.01) and high amplitude PS (HAPS/24 h, 5 ± 2:10 ± 3, p = 0.04), with amplitude, velocity, or propagating distance unchanged. There was increased activity on waking and 4/8 ceased using antegrade continence enemas.

Transcutaneous IFC increased colonic PS frequency in STC children with effects lasting 2–7 months. IFC may provide a treatment for children with treatment-resistant STC.

Varied intestinal neuromuscular pathologies are responsible for Hirschsprung disease and other forms of chronic pseudo-obstruction that are encountered in pediatrics. Pathologically distinct subtypes discussed in this review include aganglionosis, hypoganglionosis, neuronal intranuclear inclusion disease, ganglionitis, degenerative neuropathy, diffuse ganglioneuromatosis, neuronal dysplasia, malformations of the muscularis propria, degenerative leiomyopathy, leiomyositis, and mitochondriopathies. Emphasis is given to the histopathologic features that distinguish these conditions and their differential diagnoses.

After 5 years of intensive oral laxative use, up to 30% of constipated children still have an unsuccessful outcome. Children refractory to oral laxatives might benefit from regular rectal evacuation by enemas. This randomized controlled trial compared the effects of additional treatment with rectal enemas (intervention) with conventional treatment alone (oral laxatives, control) in severely constipated children.

In a tertiary hospital in the Netherlands, 100 children, aged 8–18 years, with functional constipation for at least 2 years were randomly assigned to intervention or control groups. The control group received education, behavioral strategies, and oral laxatives. The intervention group was also given 3 rectal enemas/week, reduced by 1 enema/week every 3 months. Outcome measures were defecation and fecal incontinence frequency and overall success at 12, 26, 39, and 52 weeks. Overall success was defined as 3 or more defecations/week and less than 1 fecal incontinence episode/week, irrespective of laxative use.

Defecation frequency normalized in both groups but was significantly higher in the intervention group compared with controls at 26 and 52 weeks (5.6 vs 3.9/week, P = .02, and 5.3 vs 3.9/week, P = .02, respectively). There were no significant differences between groups in reduction of fecal incontinence episodes (P = .49) and overall success rates (P = .67). After 1 year of treatment, the overall success rate was 47.1% in the intervention group versus 36.1% in the control group.

There is no additional effect of enemas compared with oral laxatives alone as maintenance therapy for severely constipated children.