Transcutaneous Electrical Nerve Stimulation Increases Rectal Activity in Children.

OBJECTIVES: Neurostimulation is increasingly used in treating bladder and bowel dysfunction, but its effect on rectal motility is obscure. The aim of the study was to evaluate the acute effect of transcutaneous electrical nerve stimulation (TENS) on rectal motility in children with overactive bladder (OAB). METHODS: In this double-blind placebo-controlled study in 20 children with OAB (mean age 8.6 ±â€Š1.8 years; 7 girls), 48-hour urodynamic monitoring including rectal manometry was performed. After 24-hours of baseline investigation without stimulation the children were randomised to either active TENS (n = 10) or placebo (n = 10). Surface electrodes were placed over the sacral bone. The exterior of active and placebo stimulators was identical. Starting in the morning, the children received either continuous TENS stimulation or placebo until bedtime. Rectal contractions were defined as pressure runs exceeding 5 cm H2O and lasting ≥3 minutes. RESULTS: At baseline there was no significant difference in proportion of time with rectal contractions in the 2 groups (TENS group median 31% [range 12%-66%] vs placebo group median 31% [range 10%-66%]; P = 0.75); however, on the day of stimulation there was more time with rectal contractions in the group receiving TENS (median 51% [range 25%-78%]) compared with placebo (median 32% [range 4%-68%]; P = 0.02). Also, there was an increase in time with rectal contractions in the TENS group (P = 0.007) but not in the placebo group (P = 0.39). The night after the TENS was disabled, rectal activity in both groups returned to baseline level. CONCLUSIONS: TENS acutely increases time with rectal contractions in children undergoing urodynamic investigation. The effect disappears when the stimulator is turned off.

Rectal motility in pediatric constipation.

OBJECTIVES: Constipation is a common disorder in children, but little is known about its etiology. Rectal impedance planimetry determines segmental rectal cross-sectional area (CSA) and pressure, allowing detailed description of rectal motility. The aim of the present study was to compare rectal motility in healthy and constipated children. METHODS: We analyzed data from 10 children (1 girl) with constipation according to the Rome III criteria, mean age 8.8 years (standard deviation ±â€Š1.2), and 10 healthy children (5 girls), mean age 9.9 years (standard deviation ±â€Š1.5). CSA was determined at 3 levels (4, 5.5, and 7 cm from the anal verge). The resting rectal motility was recorded for 30 minutes followed by a distension protocol to assess compliance. Runs of phasic rectal contractions were defined as changes of >10% from baseline CSA and lasting at least 2 minutes. Rectal dimensions were expressed as mean CSA. RESULTS: A low-amplitude contraction pattern (3%-5% of baseline CSA) with a frequency of 6 to 8/minute was present in all of the children. There was significantly more time with phasic rectal contractions in constipated children (median 38%, range [0-100]) compared with healthy children (median 8.8%, range [0-57]) (P < 0.05). The rectal CSA was higher in constipated children (median 1802 mm [range 1106-2948]) compared with healthy children (1375 mm [range 437-1861]) (P < 0.05), but compliance did not differ (constipated: median 38 mm/H2O [range 12-86] vs healthy 33 mm/H2O [range 10-63]) (P = 30). CONCLUSIONS: In children with constipation, we found phasic rectal contractions for a significantly longer period compared with healthy children, and their rectum is larger than normal.