Neurostimulation helps children’s intractable constipation, study finds

The study involved 62 patients -- 34 girls, 28 boys -- at the Murdoch Childrens Research Institute of the Royal Childrens Hospital in Melbourne, Australia. They ranged from 2 -- 16 years old, with a mean age of 7 years. Results of the three-year project are being presented by the institute's Bridget Southwell, Ph.D. who became involved in the INS due to its cross-discipline blend of medical research and development. She and pediatric surgeon Dr. John Hutson supervised the lead researcher, Dr. Yee Ian Yik, a surgeon obtaining his Ph.D. in studies of chronic constipation in children on a stipend from the Malaysian government.

The study is being expanded to typical causes of chronic constipation, and to adults. The work focused on children with slow transit constipation (STC), a problem of the upper colon.

After two to three months of treatment:

• 25 percent of the children completely stopped laxative use and 50 percent reduced it
• 57 percent of the children who began the study with fewer than three bowel movements per week (56 of the participants) improved bowel movement frequency to more than three times a week
• 87 percent of the participants decreased bypass soiling from an average of five times a week to once a week
• 87 percent of the families reported the child had an increase in urge-initiated defecation
• 95 percent of the patients who began with abdominal pain (39 participants) saw their pain reduced
• Quality of life scores by the children and parents increased 12 -- 13 points

In the study, parents were trained to apply electrode patches near the child's navel and back for an hour a day to administer electrical stimulation called inferential transcutaneous electrical stimulation (TES). TES is commonly used in physical therapy. This form delivers two separate currents that cross, much like wakes from boats on the surface of water. This pattern is believed to penetrate well, in this case delivering a therapeutic pulse to cells and nerves in the gut.

Southwell's group started to research this use of TES in 2003 after a physiotherapist noticed references about TES use in adults with bladder problems causing loose stools.

Over the past 10 years, in examining muscle and nerve cells from colon samples of patients with STC, the researchers noticed that one-third have a reduced number of nerves, while one-fourth are missing the interstitial cells of Cajal. "These little cells are a really important in quickly carrying and spreading the message to contract from nerves to muscle cells," Southwell said. "The colon contains its own nervous system that controls movement, so if these cells are low in number or missing, then the intestine is not able to push properly."

About three out of every 1,000 people have STC. While some cases do improve by adulthood, many do not, and typical treatments such as enemas have little effect, while high-fiber diets can exacerbate it. In STC, it is possible for patients to not be able to feel fecal material in their bowel prior to elimination, so a bowel movement can suddenly appear without warning. Most patients also experience bypass soiling of more liquid matter seeping past the chronic blockage. Most cases are diagnosed in infancy and half are present at birth.

Overall, 5 -- 10 percent of children experience chronic constipation. Most often, it is due to stool accumulating in lower regions of the gastrointestinal tract. In addition to initiating a trial of TES placing the electrodes over the pelvic area in 100 children who have this more common kind of chronic constipation, Southwell said, the clinicians have also tested TES in adults with STC with good results as well, she continued, adding that if the technique becomes an established treatment, it might be helpful in elderly where medications cause constipation.

"The fact that electrical stimulation can make the bowel work in these patients tells us that all the parts of the mechanism for normal functioning are present but need some additional activation or resetting," Southwell said. "We think this will be relevant to other types of constipation including constipation in the elderly."

STC was once treated by removing the large bowel, since its inability to move digested material forward effectively slows movement through the whole colon. Now some children receive a port in the abdomen through which a tube is inserted for periodic bowel washouts. The study subjects had been referred to surgery at the pediatric center and were offered to participate in the trial first.

"We are in the early stages of the research," Southwell said, "and I have discussed the method with other experts in Europe, U.K. and the U.S.A. They are interested and we hope to have other centers testing the method in the next few years. "