Constipation 'may cause bedwetting'
Some children who wet the bed may have undiagnosed and unrecognised constipation, says a study
30th January 2012 - A new study suggests that for many children who wet the bed, the underlying cause may be with their bowels and not their bladders.
Undiagnosed constipation appeared to be a frequent contributor to bedwetting (also called enuresis) among the children who took part in the research.
When these children were treated with laxatives or enemas, most stopped wetting the bed within a few months.
“Most of these kids did not have symptoms consistent with constipation and the parents had no clue,” says researcher Dr Steve Hodges, an assistant professor of urology at Wake Forest Baptist Medical Center in Winston-Salem, in the US. “What these children had was stool in their rectums, and that is the problem we addressed in this study.”
Bedwetting and the bowels
Dr Hodges says stool left in the lower intestine or rectum results in an enlarged or expanded rectum (megarectum) that can push against the bladder and reduce its capacity to hold urine. He says even though it has been known for more than two decades that this might be a cause of bedwetting, few doctors consider this when evaluating children with the condition.
Since normal constipation symptoms, as defined by the standard questions "Do bowel movements occur less often than every other day, and is the stool consistency hard?", do not always predict whether a child will have stool in an enlarged rectum, Dr Hodges and diagnostic radiologist Dr Evelyn Anthony conducted abdominal X-rays to confirm the presence of megarectum.
Their study included 30 children ranging in age from five to 15 who were being treated for bed-wetting.
X-rays revealed that all of the children had some degree of rectal expansion caused by stool. Four out of five had quantities of stool in the rectum that was consistent with constipation, despite the fact that just one in 10 had a history of constipation symptoms. When the children received laxatives or enemas to treat the problem, within three months 25 of the 30 (83%) were no longer wetting the bed.
The study appears online in the journal Urology.
Dr Hodges says that he has used the approach to successfully treat close to 200 cases of bedwetting and urinary reflux - a condition characterised by abnormal flow of urine from the bladder back toward the kidneys. “I haven’t had to operate on a child for reflux in a very long time because when we empty their rectums the reflux resolves,” he tells us.
It is estimated that in the UK more than half a million children between the ages of five and 16 regularly wet the bed. Boys are more likely than girls to wet the bed up to the age of 12, but for 12 to16 year olds there are proportionally more girls.
Dr Hodges says children evaluated for bedwetting or urinary reflux should undergo an abdominal X-ray or ultrasound to look for stool in an enlarged rectum before they are treated with drugs or surgery.
Commenting on the study by email, Dr Anne Wright, chair of the Clinical Advisory Committee for the UK charity Education and Resources for Improving Childhood Continence (ERIC) said; “The association between constipation and all forms of urinary incontinence is well known and widely accepted."
She continued: "The NICE guidelines on nocturnal enuresis [bedwetting] recommend treatment of constipation before embarking on treatment for enuresis."
Dr Wright said that constipation symptoms were often missed when parents sought help for a child who was wetting the bed, but she said that the X-ray technique used to diagnose constipation in the study would not be routinely used in the UK. She added: "This may be more safely replaced by measurement of the rectum by ultrasound, which represents a radiation-free technique of measuring the loaded rectum."