constipation is one of the most prevalent gastrointestinal disorders among children with the reported prevalence varying from about 1 - 8% in the pediatric population . it accounts for 3 - 5% of visits to pediatricians and up to 25% of visits to pediatric gastroenterologists . disease burden and estimated healthcare costs are considerable and it can significantly impair quality of life of patients in both mental and physical health aspects . in most of the cases ( 90 - 95% ) , no organic cause is found for constipation leading to the diagnosis of functional constipation in the child . common current medications for maintenance therapy include mineral oil , lactulose , milk of magnesia , polyethylene glycol powder , and sorbitol . because the etiology of the disease is not clearly understood , there is no specific treatment for functional constipation , and despite various treatments , only about half of the children with functional constipation demonstrate long - term improvement . there is growing interest about the efficacy of probiotics in the treatment of functional as well as organic gastrointestinal disorders . probiotics have been reported to be effective in the treatment of various disorders including inflammatory bowel disease , irritable bowel syndrome , travelers diarrhea , and constipation . because colonic microflora can affect the motility of the colon , an imbalance in the colonic microflora is proposed to have a role in the pathophysiology of chronic constipation . also , some kind of probiotics , such as bifidobacteria and lactobacilli , by producing acids ( lactic , acetic ) , result in lowering the ph of the colon , which in turn can enhance peristalsis of the colon and decrease colonic transit time . several reports are available on the beneficial effects of probiotics on symptoms of constipation , mainly in adults . studies showed that probiotic strains , such as b. infantis , increase defecation frequency and soften stools . however , limited information is available on the efficacy and safety of probiotics in the treatment of children with constipation and available studies have had controversial results . we evaluated the effects of adding a synbiotic containing lactobacillus sporogenes strain to mineral oil in the treatment of functional constipation in children . this controlled clinical trial was conducted on children referring with complaint of constipation to an outpatient clinic of pediatric gastroenterology , at the alzahra university hospital , isfahan city ( iran ) , from 2010 to 2011 . children 2 to 14 years of age diagnosed to have functional constipation based on the rome iii criteria were included consecutively . those with immunocompromised condition or other severe diseases , and those receiving antibiotic in the previous four weeks were not included . exclusion criteria included experiencing severe side - effects , gastroenteritis , or receiving antibiotic for any reason during the study period . considering alpha = 5% , study power = 80% , and expecting at least one score change in stool consistency scale , the sample size was calculated as 25 subjects in each group . the study was approved by the ethics committee of the azad university , najaf abad branch , and informed consent was obtained from all children 's parents . also , the study was registered in the iranian registry of clinical trials ( irct201207311579n1 ) . children were alternately allocated to the synbiotic and control groups . in the synbiotic group , subjects received synbiotic ( lactol , bioplus life sciences pvt . 1 tab/20 kg / d ) plus mineral oil ( paraffin 1 ml / kg / d ) for eight weeks . the synbiotic used in this study was composed of the following ; lactobacillus sporogenes ( 15  10 spores ) , fructo - oligosaccharides , microcrystalline cellulose , sodium starch glycolate , povidone , hypermellose stearate , sillicon dioxide , and propylene glycol . subjects in the control group received mineral oil ( paraffin 1 ml / kg / d ) for eight weeks . diagnosis of functional constipation was made according to the rome iii criteria by a pediatric gastroenterology specialist . the criteria were two or more of the following : 1 ) two or fewer stools per week , 2 ) hard or very hard stools or painful stool , 3 ) passage of very large stool , 4 ) stool retention  once a week  or more often , 5 ) history of large fecal mass in rectum , and 6 ) soiling  once a week  or more often . those who fulfiled the criteria for irritable bowel syndrome a trained general physician interviewed with each subject , and a questionnaire including demographic data and symptoms of constipation , based on the questionnaire on pediatric gastrointestinal symptoms - rome iii version , was completed . major symptoms included defecation frequency ( 1 = two times a week or less to 5 = more than three times a day ) , stool consistency ( 1 = very hard to 5 = watery ) , stool retention ( yes / no ) , and painful defecation ( yes / no ) . other symptoms included urgency , straining , passing mucus , and feeling of incomplete evacuation which were scored from 0 ( never ) to 4 ( always ) and soiling which was scored from 0 ( never ) to 5 ( every day ) . subjects were interviewed at the end of the intervention ( 8 week ) with the same questionnaire including compliance and side - effects as well , and a subjective global improvement ( sgi ) scale which was scored from 0 ( significantly worsen ) to 7 ( completely improved ) . statistical tests included independent sample t - test for comparison of parametric data and mann - whitney test for comparison of non - parametric data between the two groups . this controlled clinical trial was conducted on children referring with complaint of constipation to an outpatient clinic of pediatric gastroenterology , at the alzahra university hospital , isfahan city ( iran ) , from 2010 to 2011 . children 2 to 14 years of age diagnosed to have functional constipation based on the rome iii criteria were included consecutively . those with immunocompromised condition or other severe diseases , and those receiving antibiotic in the previous four weeks were not included . exclusion criteria included experiencing severe side - effects , gastroenteritis , or receiving antibiotic for any reason during the study period . considering alpha = 5% , study power = 80% , and expecting at least one score change in stool consistency scale , the sample size was calculated as 25 subjects in each group . the study was approved by the ethics committee of the azad university , najaf abad branch , and informed consent was obtained from all children 's parents . also , the study was registered in the iranian registry of clinical trials ( irct201207311579n1 ) . children were alternately allocated to the synbiotic and control groups . in the synbiotic group , subjects received synbiotic ( lactol , bioplus life sciences pvt . 1 tab/20 kg / d ) plus mineral oil ( paraffin 1 ml / kg / d ) for eight weeks . the synbiotic used in this study was composed of the following ; lactobacillus sporogenes ( 15  10 spores ) , fructo - oligosaccharides , microcrystalline cellulose , sodium starch glycolate , povidone , hypermellose stearate , sillicon dioxide , and propylene glycol . subjects in the control group received mineral oil ( paraffin 1 ml / kg / d ) for eight weeks . diagnosis of functional constipation was made according to the rome iii criteria by a pediatric gastroenterology specialist . the criteria were two or more of the following : 1 ) two or fewer stools per week , 2 ) hard or very hard stools or painful stool , 3 ) passage of very large stool , 4 ) stool retention  once a week  or more often , 5 ) history of large fecal mass in rectum , and 6 ) soiling  once a week  or more often . those who fulfiled the criteria for irritable bowel syndrome a trained general physician interviewed with each subject , and a questionnaire including demographic data and symptoms of constipation , based on the questionnaire on pediatric gastrointestinal symptoms - rome iii version , was completed . major symptoms included defecation frequency ( 1 = two times a week or less to 5 = more than three times a day ) , stool consistency ( 1 = very hard to 5 = watery ) , stool retention ( yes / no ) , and painful defecation ( yes / no ) . other symptoms included urgency , straining , passing mucus , and feeling of incomplete evacuation which were scored from 0 ( never ) to 4 ( always ) and soiling which was scored from 0 ( never ) to 5 ( every day ) . subjects were interviewed at the end of the intervention ( 8 week ) with the same questionnaire including compliance and side - effects as well , and a subjective global improvement ( sgi ) scale which was scored from 0 ( significantly worsen ) to 7 ( completely improved ) . statistical tests included independent sample t - test for comparison of parametric data and mann - whitney test for comparison of non - parametric data between the two groups . during the study period 30 children were included in each group ( mean age = 5.0  2.9 years , 55% female ) ; all of them completed the study [ figure 1 ] . the two groups were similar in age , gender , and baseline symptoms except stool frequency which was slightly lower in the control group ( p = 0.024 ) [ table 1 ] . after the study , there was a significant improvement in most symptoms of constipation in both the synbiotic and control groups . however , improvements were greater in the synbiotic group regarding defecation frequency ( even after controlling for baseline difference by ordinal regression test ) , straining , sense of incomplete evacuation , and the frequency of fecal incontinence ( p < 0.05 to < 0.001 ) [ table 2 ] . according to the sgi scale , symptoms were moderately and significantly improved in 13.3% and 86.6% of the subjects respectively , in the symbiotic group , while in the control group , improvement of symptoms was moderate in 36.6% and significant in 40% of subjects , which showed a significantly better global improvement in the synbiotic group ( p < 0.001 ) [ table 2 ] . patients flow diagram comparison of demographic data and baseline clinical characteristics between the two groups comparison of symptoms at the end of intervention between the two groups according to a difference between the two groups in baseline defecation frequency , we conducted a multivariate analysis to find factors associated with sgi results by controlling age , gender , kind of intervention , and baseline symptoms . among the mentioned factors , only receiving synbiotic plus mineral oil compared with mineral oil alone was significantly associated with more global improvement ( estimate coefficient = 2.359 , ci95% : 0.862 to 3.857 , p = 0.002 ) [ table 3 ] . regression ordinal model on possible predictors of global improvement no severe side - effect was reported in any group . reported side - effects were bloating ( 3.3% ) , diarrhea ( 3.3% ) , mild epigastric pain ( 3.3% ) , vomiting ( 3.3% ) , and abdominal pain plus itching and scar in the anal region in one case ( 3.3% ) . according to a difference between the two groups in baseline defecation frequency , we conducted a multivariate analysis to find factors associated with sgi results by controlling age , gender , kind of intervention , and baseline symptoms . among the mentioned factors , only receiving synbiotic plus mineral oil compared with mineral oil alone was significantly associated with more global improvement ( estimate coefficient = 2.359 , ci95% : 0.862 to 3.857 , p = 0.002 ) [ table 3 ] . no severe side - effect was reported in any group . reported side - effects were bloating ( 3.3% ) , diarrhea ( 3.3% ) , mild epigastric pain ( 3.3% ) , vomiting ( 3.3% ) , and abdominal pain plus itching and scar in the anal region in one case ( 3.3% ) . the aim of the present study was to evaluate the effectiveness of adding probiotic to the conventional treatment of childhood functional constipation . according to the results , adding a synbiotic which contained lactobacillus sporogenes to mineral oil resulted in more improvement in several symptoms of constipation compared with mineral oil alone . multivariate analysis with control of baseline symptoms and age and gender also approved these results . limited data are available on the efficacy of probiotics in the treatment of constipation in children . in one study conducted by bekkali and colleagues , children with functional constipation received a mixture of probiotics composed of bifidobacteria and lactobacili for 4 weeks . results showed that the average of defecation frequency increased from 2/week at the beginning to 3.8/week at the end of the therapy . however , similar to our results , fecal incontinence decreased and no important side - effect was observed . in another study by bu and colleagues , children with constipation were allocated to three groups of lactobacillus casei rhamnosus , magnesium oxide , and placebo . the results of this study showed that the probiotic was as effective as the magnesium oxide , while it did not have its possible side - effects . in a study conducted by khodadad and colleagues , children with constipation received paraffin ( 1.5 ml / kg / d ) , synbiotic composed of lactobacillus and bifidobacteria , or a combination of synbiotic and paraffin . the results showed that defecation frequency increased significantly in the combination group compared with the paraffin alone . but no beneficial effect was observed for stool form , incontinence , or painful defecation . similar to our study , no side - effect was reported in the combination group while leakage of paraffin was a reported side - effect in those who received paraffin alone . in contrast to the above mentioned trials showing the beneficial effects of probiotics in the treatment of childhood constipation , banaszkiewicz and colleagues did not find beneficial effects of adding lactobacillus gg to lactose 70% over lactose alone . differences among the results of available reports could be due to differences in the probiotic that was used ; some studies used mixture compound while others used a single - strain probiotic . available reports , however , are in favor of using probiotics as an adjunctive to other conventional therapies of childhood constipation . the possible mechanisms by which probiotics are beneficial in the treatment of constipation are not well studied . available reports are focused on colonic transit time ; however , more studies are needed in this regard . there was a difference between the two groups in baseline characteristics possibly because of alternate allocation which is not qualified as randomization ; however , we conducted a multivariate analysis to control the covariates and the results confirmed the beneficial effects of adding synbiotic to mineral oil . also , it was ethically not possible to run a placebo - controlled group which received placebo alone ; however , it was possible to add a placebo in the mineral oil group and our study has an important limitation in this regard . and finally , we had no follow - up to investigate the long - term effects of the intervention . the results of the present study showed that adding a synbiotic containing lactobacillus sporogenes to the routine treatment ( mineral oil ) of constipation in children can significantly increase improvement in symptoms , without specific side - effects . further studies evaluating and comparing other synbiotic agents , either alone or along with other standard treatments , single or mixture of probiotics , and studies with longer follow - ups are warranted . also , studies are needed on the possible mechanisms of action of probiotics in this regard .
background : functional constipation is one of the most prevalent childhood gastrointestinal disorders . we evaluated effects of adding a probiotic to mineral oil in the treatment of functional constipation in children.materials and methods : this controlled trial was conducted on 60 children ( 2 to 14 years old ) with functional constipation ( rome iii criteria ) . 
 children were allocated to receive the synbiotic ( lactol , composed of lactobacillus sporogenes , 1 tab/20 kg / d ) plus mineral oil ( paraffin 1 ml / kg / d ) or the mineral oil alone for two months . 
 symptoms of constipation including defecation frequency , stool form , strain and pain at defecation , incomplete evacuation and soiling were assessed and compared before and after the intervention . after the treatment period , the two groups were also compared with regards to subjective global assessment of improvement.results:after the treatment , stool frequency increased in both groups ( p < 0.001 ) , with greater increase in synbiotic + mineral oil group ( p = 0.001 ) . 
 frequency of hard / very hard stool and frequency of painful defecation decreased similarly in both groups ( p < 0.001 ) . 
 straining at defecation , incomplete evacuation , and soiling decreased in both groups ( p < 0.001 ) , but more decrease was seen in the synbiotic + mineral oil group ( p < 0.05 ) . 
 finally , there was a better global improvement in the synbiotic + mineral oil group ( p < 0.05 ) . 
 no severe side - effects were observed in any group.conclusion:adding the synbiotic lactol ( containing lactobacillus sporogenes ) to mineral oil can increase the improvement in the constipation symptoms of children without specific side - effects .