Childhood constipation and fruit and vegetable intake

Constipation is a common problem among children which adversely affects the daily life of both children and parents. It leads to a high number of medical visits and generates healthcare costs as a result of the procedures involved in diagnosing it as well as the associated medical problems. Its frequency is vary from 7% to 28%[1,2] and girls are more affected than boys^[3]. Constipation is seen frequently in children at about1 year up to 9 years of age^[1,3].

According to Benninga and colleagues^[4] the definition of childhood constipation is the occurrence of two or more of the following characteristics during the previous 8 weeks: (i) frequency of bowel movements less than three per week, (ii) more than one episode of fecal incontinence per week, (iii) the passing of stools so large that they obstruct the toilet, (iv) retentive posturing and withholding behaviour, and (v) painful defecation. The pathophysiology of constipation in children is not completely known. Two pathophysiologic mechanisms are used to explain constipation. The first of these is colonic inertia (slowtransit constipation), in which a failure of peristalsis that moves luminal contents through the colon prolongs the time for bacterial degradation of solids and more time for salt and water absorption, thus dramatically reducing stool frequency and stool weight. Interestingly, water and solids appear to be reduced proportionally in the stool of patients with constipation. The second mechanism is the outlet functional obstruction, in which an abnormal function of the pelvic floor or of rectum and anus results in transient obstruction and dyschezia. It is known that dietary factors such as a low fiber diet and low caloric intake are associated with constipation^[5].

Fruits and vegetables are particularly interesting for child health for their content of minerals, antioxidant vitamins, phytochemicals and dietary fiber. All these substances are related to lower risk for the development of health problems, such as certain types of cancer, cardiovascular diseases, type 2 diabetes, obesity, diverticulosis, and especially constipation^[6]. Diet, particularly dietary fiber, has often been regarded as an important determinant of constipation, although personal factors may be important as well^[3,7]. Dietary fiber is known to exert a beneficial effect on constipation as a result of its fecal bolus mass-incrementing effect, water retention properties, and increase in colon bacteria and gas production, with an acceleration of colon transit^[7]. Our study group in Turkey found that, compared to non-constipated children, those who were constipated had a lower consumption of fruit and vegetables and a higher consumption of bread, biscuits and macaroni which contained low fiber[1]. Comas and Polanco^[8] showed the same results in Spain. Today, it is clear that low dietary fiber intake is a major risk factor for childhood constipation.

Constipation is a problem both in developed and developing countries. In the world literature, there are some studies reporting the relationship between fruit and vegetable consumption and constipation, but very few pertain to children. According to Dennison and colleagues^[9] the majority of children do not consume the recommended number of fruit and vegetable servings/day. In this age group, over 70% of the population consume less than 3 portions of fruit every day on average. Naturally, those children are at risk for constipation^[4]. Serving vegetables several times a day (i.e., for snacks, lunch, and dinner) and serving more than one vegetable at a time are ways to increase children’s consumption of vegetables. Encouraging parents and day care providers to not only offer a variety of fruits and vegetables, but to also model eating them is probably one of the best ways to increase children’s fruit and vegetable consumption^[9].

In conclusion, the most important preventive factors against childhood constipation are water, fruit and vegetable consumption and training on the use of the toilet. This preventive intervention should be reinforced at school. Family physicians, pediatricians, nurses, psychiatrists and paediatric surgeons should be aware of the potential risks of childhood constipation as a community problem. Detailed studies are needed to clarify the effects of fruit and vegetable consumption on childhood constipation.