Improvement of quality of life in children with slow transit constipation after treatment with transcutaneous electrical stimulation

Neuromodulation for constipation: sacral and transcutaneous stimulation

Constipation is a frequently occurring digestive ailment that is usually treated conservatively. Neuromodulation is altering function of an organ by altering neural activity. This paper reviews methods of neuromodulation used to treat constipation. This includes direct stimulation of sacral nerves and stimulation across the skin. Direct stimulation of sacral nerves is the most well developed method and is presented in detail. It is generally accepted that the mechanism of action is modulation rather than stimulation so it is called sacral neuromodulation (SNM). SNM involves percutaneous placement of an electrode in the third sacral foramen and implanting a stimulating device under the skin in the buttocks. SNM is founded on the physiological principle that activity in one neural pathway modulates pre-existing activity in another through synaptic interaction. The mechanism of action in constipation may be neuromodulation of the extrinsic neural control of the large bowel or modulation of reflexes inhibiting large bowel function. Limited evidence is available to assess the outcome of SNM in constipation. Results in the medium term seem promising for selected patients with idiopathic slow and normal transit constipation not responding to optimal conservative treatment. Adverse events include electrode migration and infection. The availability of a testing phase provides a predictor of treatment outcome. In addition, transcutaneous stimulation using sticky pad electrodes over the lumbosacral region or acupuncture points has been reported to improve constipation symptoms. In general, the level of evidence is low and further studies are needed.

Daily transabdominal electrical stimulation at home increased defecation in children with slow-transit constipation: a pilot study

PURPOSE

Transcutaneous electrical stimulation (TES) (3 sessions/wk) over the abdomen stimulated bowel functions in a randomized controlled trial. This pilot study assessed whether daily TES at home with a safe, portable machine would be possible and more efficacious than trial results.

METHODS

Eleven patients (6 male/5 female; mean age, 14 years; range, 12-18 years) with slow-transit constipation who relapsed or responded poorly in the trial were recruited (11 +/- 5 months later). An EPM-IF-4160 (Fuji Dynamics, Hong Kong) portable machine (sine waveform, 4 kHz carrier frequency, 80-160 Hz beat frequency, intensity <33 mA) delivering interferential current (2 electrodes over epigastrium + 2 over kidneys) was applied 1 hour daily at home. Continence diaries were kept for 1 month before and 2 months during treatment.

RESULTS

All children completed more than 1 month of treatment after baseline recording. Defecation increased in 9 of 11 children, and soiling decreased in 4 of 11 children. There was a significant increase in total episodes of defecation per week (mean +/- SD, 2.5 +/- 2.1 vs 6.7 +/- 4.4; P = .008) and a nonsignificant decrease in soiling (3.8 +/- 1.6 vs 1.1 +/- 0.5 episodes/wk, P = .1). Daily stimulation does not affect abdominal pain. No adverse events occurred.

CONCLUSIONS

Daily TES at home is safe and significantly improved bowel function in children who did not respond to 3 times per week of TES. Home TES may be a novel treatment of intractable slow transit constipation, avoiding hospital visits.

Gastrointestinal transit in children with chronic idiopathic constipation

Chronic constipation in children is common and produces significant morbidity. Identification of the site of dysmotility in constipation may determine the cause and permit directed management. Scintigraphy differentiates constipated patients with anorectal hold-up from those with colonic slowing. Adults with colonic slowing demonstrate variation in the site of hold-up. However, in children with colonic slowing, variability in the site of hold-up has not been investigated.

PURPOSE

The current study aimed to characterise colonic transit patterns in 64 children with chronic idiopathic constipation.

METHODS

Scintigraphic images were grouped visually by their transit patterns. Intra-observer variation was assessed. Scintigraphic data were analysed quantitatively.

RESULTS

Visual analysis of scintigraphy studies demonstrated normal transit (11/64), anorectal hold-up (7/64) and slow colonic transit (46/64). Transit characteristics in the slow transit group demonstrated three possible subgroups: pancolonic slowing (28/46), discrete hold-up in the transverse colon (10/46) and abnormal small and large bowel transit (8/46). Kappa testing demonstrated consistent characterisation (k = 0.79). Statistical analysis of scintigraphic data demonstrated highly significant differences from normal (P < 0.001) in the subgroups.

CONCLUSION

Scintigraphy demonstrates three possible transit patterns in children with chronic constipation secondary to slow colonic transit.

Standard medical therapies do not alter colonic transit time in children with treatment-resistant slow-transit constipation

BACKGROUND

Slow transit constipation (STC) is a form of chronic constipation characterised by prolonged passage of faecal matter through the colon. It is diagnosed by demonstrating delayed colonic transit on gastrointestinal transit studies. Traditionally, radio-opaque marker studies are performed. Recently, radioisotope nuclear transit studies (NTS) have been used in our centre to assess gastrointestinal transit time. This study aimed to evaluate if there are changes in colonic transit in STC children resistant to standard medical treatment over a prolonged period.

METHODS

Children with STC resistant to standard medical therapy for > or =2 years who had undergone two separate NTS to assess their colonic transit (where the first study had identified slow colonic transit without anorectal retention) were identified after ethical approval. The geometric centre (GC) of radioisotope activity at 6, 24, 30 and 48 h was compared in the two transit studies to determine if changes occurred.

RESULTS

Seven children (4 males) with proven STC resistant to standard medical therapy and two transit studies performed at different times were identified. Mean age was 7.0 years (5.4-10.8 years) at first study, and 11.4 years (9.7-14.2 years) at second study, with a mean of 4.4 years (1-8.5 years) between studies. There was no significant difference in colonic transit at any timepoint in the two tests (paired t test).

CONCLUSIONS

We conclude that nuclear transit studies are reproducible in assessing slow colonic transit in children with treatment-resistant STC and demonstrate that conventional medical treatment over many years has no effect on underlying colonic motility.