Bedwetting isn't always due to problems with the bladder but constipation could be the culprit. This might necessitate a long, costly and difficult quest to cure nighttime wetting.
Wake Forest Baptist Medical Centre researchers found that 30 children and adolescents, aged five to 15 years, who sought treatment for bedwetting all had large amounts of stool in their rectums, despite the majority having normal bowel habits.
After treatment with laxative therapy, 25 of the children (83 percent) were cured of bedwetting within three months, the journal Urology reports.
"Having too much stool in the rectum reduces bladder capacity," said Steve J. Hodges, assistant professor of urology at Wake Forest Baptist, who led the research, according to a Wake Forest statement.
"Our study showed that a large percentage of these children were cured of nighttime wetting after laxative therapy. Parents try all sorts of things to treat bedwetting -- from alarms to restricting liquids. In many children, the reason they don't work is that constipation is the problem."
Hodges said the link between bedwetting and excess stool in the rectum, which is the lower five to six inches of the intestine, was first reported in 1986.
However, he said the finding did not lead to a dramatic change in clinical practice, perhaps because the definition of constipation is not standardized or uniformly understood by all physicians and lay people.
"The definition for constipation is confusing and children and their parents often aren't aware the child is constipated," said Hodges.
"In our study, X-rays revealed that all the children had excess stool in their rectums that could interfere with normal bladder function. However, only three of the children described bowel habits consistent with constipation."