Chronic Constipation in Overweight ChildrenFrom the Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, UIC College of Medicine at Peoria and Children's Hospital of Illinois at OSF St. Francis Medical Center, Peoria, Illinois Correspondence: Sudipta Misra, MD, Associate Professor of Clinical Pediatrics, 320 E Armstrong, Peoria, IL 61603. Electronic mail may be sent to smisra{at}uic.edu. Background: Obesity and functional constipation seem to share a common biopsychosocial model of causation. Though chronic constipation can significantly affect the quality of life of an overweight child, this association has not been highlighted in the literature. The purpose of this study was to compare the proportion of overweight children among children with chronic constipation with a control group of children with normal bowel habits. Methods: Retrospective chart review with a control population. One hundred one consecutive children 5–18 years of age referred to the Subspecialty Clinic for functional constipation were the study group. The control group consisted of 100 consecutive children from the general pediatric practice seen for physicals and minor illnesses. Children with a body mass index (BMI) of >85 percentile from the National Institutes of Health (NIH) 2000 chart were classified as overweight. Results: The control and study groups were statistically comparable in mean age (10.97 ± 3.83 years and 8.07 ± 2.56 years, respectively) and gender ratio (58 males in each group). Thirty children in the control group and 44 in the study population were overweight (p < .05). Among children with chronic constipation, the group of overweight children was male predominant (70.45% vs 47.36%, p < .05), had increased incidence of psychological/behavioral problems (45.45% vs 22.8%, p < .05), and was more likely to fail treatment (40.9% vs 21.05%, p < .05). There was no significant difference in the clinical profile of constipation, such as mean duration of constipation before presentation, sex ratio, incidence of painful defecation, and soiling and frequency of defecation between these 2 groups. Conclusions: There appears to be an association between chronic severe constipation and being overweight. Children with constipation are more likely to be overweight when compared with controls. Among children with chronic constipation, overweight individuals seem to constitute a distinct clinical group. This group is male predominant, has increased incidence of psychological/behavioral disorders, and is more likely to fail treatment. Obesity is a major health problem in children and adolescents in the United States and other developed countries. Though various medical and psychological complications have been reported in overweight children,1–3 an association between constipation and being overweight has been made in only 1 recent publication.4 This study was prompted by the clinical observation that there appeared to be a preponderance of overweight children among those referred for management of chronic constipation to the pediatric gastroenterology clinic. A review of the psychological profile of these 2 groups of children revealed marked similarities such as low self-esteem, social isolation, and perceived lack of self-control.3,5,6 The purpose of this study was to compare the proportion of overweight children among children with chronic constipation with a control group of children with normal bowel habits. We also compared the clinical profile of constipation between overweight and nonoverweight children to document whether overweight children with constipation constitute a distinct clinical subgroup.
This was a retrospective case-control study by chart review involving children between the ages of 5 and 18 years. The Peoria Community institutional review board approved the study.
Selection of Study Group
Selection of Control Population
Assessment of BMI
Recording and Collection of Data
Charts of these subjects were reviewed to record the clinical profile of
constipation. Response was defined as (1) soft bowel movements without
discomfort, (2) more frequent stooling than on presentation (usually more than
once in 2 days), and (3) soiling less than once a week. The response was
recorded from the last available clinic visit notes and corresponding stool
log.
Comparison of Constipation and Control Groups The constipation and control groups were comparable in age and sex distribution. The mean age of 100 children in the control group was 10.97 ± 3.83 years, whereas the mean age for the 101 children with constipation was 8.07 ± 2.56 years (p > .05). Both the groups had 58 male subjects. The BMIs of 30 (30%) children in the control group and 44 (43%) children in the constipation group were above 85th percentile for their sex and age in the CDC chart. This difference in the number of overweight children between the constipation and control groups was statistically significant (p < .05).
Further Analysis of the Study Group
There appeared to be no significant difference in the clinical profile of constipation at presentation between the overweight and nonoverweight children (Table I). The duration of constipation at presentation was 32.22 months in children who were not overweight and 40.76 months in those who were (p > .05). Similarly, the average weekly frequency of bowel movement at presentation was 1.8 in overweight children and 2.4 in the rest (p > .05). The average age of toilet training was 32.77 months in overweight children, whereas it was 34.64 months in the other group (Table I). Among the overweight children (n = 44), 19 (43%) could feel the urge to defecate, 10 (23%) did not feel the urge, and 15 (34%) children were not sure. Among the nonoverweight children (n = 57), 15 (26%) could feel the urge, 7 (12%) did not feel the urge, whereas 35 (61%) were not sure. Though soiling was more frequently reported among overweight children, the difference did not reach statistical significance. Parents reported behavioral/psychiatric disorders in 30 children. Attention deficit hyperactivity disorder (ADHD) was most common (n = 21), followed by psychosis, depression, victim of child abuse, aggressive and self-destructive behaviors. The occurrence of psychiatric/behavioral disorders was more frequent among overweight children with constipation (45.45% vs 22.8%; p < 05; Table I). Failure to respond to anticonstipation therapy was documented in 30 children. Eighteen of these children were overweight, which constituted approximately 40.9% of overweight children with constipation. When compared with failure rate in children who were not overweight (n = 12, 21.05%), the difference was statistically significant (p < .05).
Quality of life is poor in most overweight children. They have low self-esteem, lack of self-control, which results in failure to lose weight, and end up as loners with few or no friends.3,5,6 This psychological profile matches children with chronic constipation and encopresis who have been reported to have poor self-esteem, lack self-control, and are often outcasts due to social withdrawal and peer rejection.7,8 It has been reported by us and others that resolution of constipation leads to an improved quality of life in neurologically normal children.9,10 It can be assumed that recognition and treatment of constipation can have a positive impact on the lifestyle of overweight children. Despite marked similarity in the psychological profiles of children with chronic constipation and those who are overweight, an association between these 2 has not been highlighted. Only 1 recent uncontrolled questionnaire-based study reported an increased incidence of chronic constipation with soiling in morbidly obese children.4 The goal of our study was to evaluate the incidence of overweight children among those with chronic constipation. Accordingly, we extended the definition of overweight to include an at-risk population for overweight-related complications (BMI between 85th and 95th percentile).11 Though we reached a similar conclusion as Fishman et al,4 some questions arose on the validity of such global conclusion. We compared a group of children being treated for chronic constipation with a control group. These 2 groups were comparable in age and sex distribution. Both groups were samples of similar population, being drawn from clinics located in the same geographic location during the same time frame. The chance of encountering an overweight child was more among those with chronic constipation than in the control group. However, the relationship between overweight and constipation does not seem to be a simple one. The reported rate of incidence of pediatric constipation in the community varies widely between 0.3% and 28%.8,12,13 It is estimated that about 3% of children seen at the pediatricians' office and about 30% of those seen by pediatric gastroenterologists have constipation.7 It is known that mild to moderate constipation is almost a normal variant. These children recover spontaneously or with minimal intervention. However, children referred to subspecialists (our study group) have the so-called resistant constipation not amenable to treatment by the primary care physicians. It will be interesting to review our findings in light of a primary care–based study comparing the proportion of overweight children among those with constipation and the ease with which these children are treated. It is likely that such a population will have more children with mild to moderate constipation. Therefore, the difference in the prevalence of constipation between overweight and normal-weight children may not be so obvious in the primary care setting. To the best of our knowledge, no such study is available in the literature. However, findings from the second part of our study, which suggested that the overweight children with chronic constipation constituted a distinct subgroup of pediatric constipation, indirectly support such a possibility. We divided the children with constipation into 2 groups, according to whether they were overweight or not. Both groups were of comparable age and had a comparable clinical picture at presentation (Table I). Children in both the groups had constipation for nearly 3 years before being seen at the subspecialty clinic. The severity of constipation at presentation, as measured by the frequency of defecation, did not differ significantly between these 2 groups. Early toilet training has been cited as an etiologic factor for functional constipation.14 However, both groups underwent toilet training around the same age. Though male children are reported to be more susceptible to constipation,15–17 no such difference was seen between the constipation and control groups. However, the group of overweight children with constipation was significantly male predominant. The overweight children also had an increased incidence of behavioral or psychological problems such as ADHD. Furthermore, a significantly higher number of overweight children failed to respond to therapy. It is possible that, at the primary care level where mild to moderate constipation predominates, there may not be a significant difference in the incidence of constipation between overweight children and their peers. However, the difference is unmasked at the subspecialty level, where children with constipation not amenable to usual therapy are referred. It can be argued that diet may play an important role as an etiologic factor in both obesity and constipation.18 It is not known whether successful treatment of chronic constipation leads to weight loss in overweight children. A comparison of the incidences of overweight and constipation among siblings may offer some insight into genetic predisposition vs the role of environmental factors in causing these 2 disorders. This study was not designed to answer other questions, which are best addressed by larger prospective studies. Retrospective studies, such as the present one, can have subjective interpretation or missing clinical data points. However, the data points in this patient population were well defined and standardized. BMI calculation was based on standard weight and height measurements. All children in the constipation group had their history recorded on the same preprinted form, were treated with a set protocol, and progress was defined by the stool log rather than historical recollection of the parents. This contributed to the objective comparability of clinical data among the children with constipation.
In light of our findings and complementary findings reported in a recent study,4 we conclude that there is a linkage between chronic constipation and being overweight. The overweight children who develop chronic constipation tend to respond poorly to therapy compared with their peers without weight problems. Primary care physicians caring for overweight children should be aware of this possibility and should proactively look for coexistent chronic constipation. At the pediatric gastroenterology clinic, overweight children with chronic constipation should be monitored closely as they are more likely to fail medical treatment. A community-based controlled study on the prevalence of constipation in overweight children is indicated for an in-depth understanding of this problem. Pediatric GI nurses Carol Strube, RN, Sharon Flexsenhar, RN, Maureen Knox, RN, and the staff of the pediatric subspecialty clinic have been invaluable in supporting the study. We gratefully acknowledge their help. Received for publication March 22, 2005. Accepted for publication November 7, 2005.
Journal of Parenteral and Enteral Nutrition, Vol. 30, No. 2,
81-84 (2006) This article has been cited by other articles:
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MATERIALS AND METHODS
RESULTS
2 and t tests were used for statistical
analysis. 
