analyses were performed using data from the year 2008 from the ims hospital disease database , which comprises data on about 34% of all acute hospital beds in belgium and includes information on patient demographics , drug use , diagnoses , and admissions . the average cost of chronic constipation per day in hospital was  441 , and the most common drug treatments prescribed were osmotically acting laxatives . this study was a single country ( belgium ) , retrospective database study of adult patients hospitalized in 2008 ( the most recent available data at the time when the study was initiated ) with idiopathic constipation or a constipation - related complication as the principal diagnosis . since 1991 , belgian hospitals have had to register case mix data for each admission in a minimum basic data set ( mbds ) , to receive funding from the health care payer . then , a subset of the national database , consisting of hospitals that have given written authorization to do so , is anonymized ( on both the hospital and the patient level ) and transmitted to ims , constituting the hdd . the panel of hospitals is representative of the belgian population in terms of geographical dispersion , hospital size , and type of center ( general hospital vs academic hospitals ) , so national prevalence figures for belgium can easily be extrapolated from the database . the unit in the hdd is the  hospital stay , either in a day clinic setting ( meaning that the patient does not stay overnight ) or as a full hospitalization ( at least one overnight stay ) . data recorded at the stay level comprise the los , the international statistical classification of diseases and related health problems version 9 ( icd-9 ) diagnoses and procedure codes , the type of admission , the los in the different services , and the type of discharge . a separate table lists all the drugs that were invoiced over the course of the stay ( number of units , dose , and cost ; prescription dates are not available , however ) with the corresponding anatomical therapeutic chemical ( atc classification system ) codes . the database also includes demographic data at the patient level ( age and sex ) . within one calendar year , all the stays related to the same patient can be tracked through a unique patient identification number attributed at the beginning of each calendar year . hospital stays were selected based on icd-9 diagnostic codes . because there is no specific code in the icd-9 nomenclature for chronic constipation , the code corresponding to constipation ( 564.0 ) all adult patients ( age 20  years ) having that code as a principal diagnosis were retained . due to the coding of age by ranges and adult had to be defined according to the closest available age range ( 20  years and older ) . concomitant diagnoses ( i.e. , at the time of constipation - related hospitalization ) corresponding to constipation - related complications were also retrieved for these patients . the constipation - related complications retained for this analysis were  anal fissure and fistula ( icd-9 diagnosis code 565 ) ,  fecal impaction ( 560.39 ) ,  impaction of intestine ( 560.30 ) ,  rectal prolapse ( 569.1 ) , intestinal obstruction ( 560 , excluding 560.30 and 560.39 ) was not included as icd-9 coding does not allow obstruction resulting from constipation to be distinguished from obstruction resulting from another organic cause such as stenosis . adult patients having constipation as a secondary diagnosis but in combination with a primary diagnosis corresponding to one of the above - mentioned constipation - related complications were also included in the study population . as a second step , exclusion criteria were applied . because diagnoses are coded at the moment of discharge , we assumed that patients hospitalized with a principal diagnosis of constipation were likely to suffer from chronic constipation . the same assumption was made for patients who experienced one of the complications of interest , as such complications are not likely to occur in cases of acute constipation . however , as the study focused on patients with primary / idiopathic constipation , cases where constipation was likely to be directly attributable to another condition were excluded . therefore , stays during which a concomitant diagnosis ( principal or secondary ) of colorectal cancer ( icd-9 codes 153 and 154 ) , ulcerative colitis ( icd-9 code 556 ) or crohn 's disease ( icd-9 code 555 ) had been recorded were removed from the study sample . similarly , stays where a dilatation of rectum ( icd-9 code 96.22 ) or a dilatation of anal sphincter ( icd-9 code 96.23 ) was performed were also withdrawn from the sample , as these procedures were possible extraneous causes of secondary constipation . the identification of cases of possibly drug - induced ( as opposed to idiopathic ) constipation was based on the documented administration of specific drugs well described in the literature as prone to inducing constipation:710 opioids ( atc code n02a ) , calcium - antagonists ( atc c08 ) , antipsychotics ( atc n05a ) , and antidepressants ( atc n06a ) . patients receiving one of these drugs during any hospitalization over the course of the calendar year ( not necessarily related to constipation ) were assumed to be  drug - induced constipation patients . idiopathic cases were considered the main population of interest while potentially drug - induced cases were analyzed as a separate cohort . the primary study endpoints were the average cost per day and the average los in hospitalizations related to chronic idiopathic constipation . for a given stay , the hospitalization costs consist of three components : drug costs , room / bed costs , and procedure costs . room / bed costs and procedure costs were obtained by merging the data from the database with average costs per all patient refined - diagnosis related groups ( apr - drg)/severity level as calculated from the financial data files that all the belgian hospitals are legally required to send twice a year to the belgian authorities . these costs are published on the website of the ministry of public health ( latest available : data year 2008).13 costs were then extrapolated to 2011 based on the progression in costs per apr - drg as observed between 2001 and 2008 in the same published data using a geometric extrapolation . different variables reflecting the burden of the disease were also calculated as secondary endpoints : mortality during the stay , laxative drug use , and use of surgical procedures in patients with chronic idiopathic constipation . age groups taken into account in this study were adult patients below and above 65  years . the use of laxatives was tracked in the database using the atc codes as available in 2011 . the following categories of laxatives were taken into consideration : softeners and emollients ( atc a06aa ) , contact laxatives ( a06ab ) , bulk producers ( a06ac ) , osmotically acting laxatives ( a06ad ) , enemas ( a06ag ) , and glycerol ( a06x01 ) . the list of procedures of interest , established after discussions with an expert gastroenterologist , included the following items :  manual reduction of rectal prolapse ( icd-9 code 96.26 ) ,  proctoclysis ( icd-9 code 96.37 ) ,  removal of impacted feces ( icd-9 code 96.38 ) ,  other transanal enema ( icd-9 code 96.39 ) , and data were analyzed using sas software version 9 ( sas institute , cary , nc , usa ) . given the skewed distribution , average costs are also reported with their range ( minimum and maximum ) . average daily cost and los were also adjusted for age , gender , and other descriptive variables ( presence of a concomitant diagnosis of cancer , presence of constipation - related complications , use of constipation - related medications / treatments , and admission through emergency unit ) with multivariate regression models , using a gamma distribution and a log - link function . this study was a single country ( belgium ) , retrospective database study of adult patients hospitalized in 2008 ( the most recent available data at the time when the study was initiated ) with idiopathic constipation or a constipation - related complication as the principal diagnosis . since 1991 , belgian hospitals have had to register case mix data for each admission in a minimum basic data set ( mbds ) , to receive funding from the health care payer . then , a subset of the national database , consisting of hospitals that have given written authorization to do so , is anonymized ( on both the hospital and the patient level ) and transmitted to ims , constituting the hdd . the panel of hospitals is representative of the belgian population in terms of geographical dispersion , hospital size , and type of center ( general hospital vs academic hospitals ) , so national prevalence figures for belgium can easily be extrapolated from the database . the unit in the hdd is the  hospital stay , either in a day clinic setting ( meaning that the patient does not stay overnight ) or as a full hospitalization ( at least one overnight stay ) . data recorded at the stay level comprise the los , the international statistical classification of diseases and related health problems version 9 ( icd-9 ) diagnoses and procedure codes , the type of admission , the los in the different services , and the type of discharge . a separate table lists all the drugs that were invoiced over the course of the stay ( number of units , dose , and cost ; prescription dates are not available , however ) with the corresponding anatomical therapeutic chemical ( atc classification system ) codes . the database also includes demographic data at the patient level ( age and sex ) . within one calendar year , all the stays related to the same patient can be tracked through a unique patient identification number attributed at the beginning of each calendar year . hospital stays were selected based on icd-9 diagnostic codes . because there is no specific code in the icd-9 nomenclature for chronic constipation , the code corresponding to constipation ( 564.0 ) all adult patients ( age 20  years ) having that code as a principal diagnosis were retained . due to the coding of age by ranges and the unavailability of exact ages in the hdd , adult had to be defined according to the closest available age range ( 20  years and older ) . concomitant diagnoses ( i.e. , at the time of constipation - related hospitalization ) corresponding to constipation - related complications were also retrieved for these patients . the constipation - related complications retained for this analysis were  anal fissure and fistula ( icd-9 diagnosis code 565 ) ,  fecal impaction ( 560.39 ) ,  impaction of intestine ( 560.30 ) ,  rectal prolapse ( 569.1 ) ,  hemorrhoids ( 455 ) , or  peri - anal thrombosis ( 453.8 ) .  intestinal obstruction ( 560 , excluding 560.30 and 560.39 ) was not included as icd-9 coding does not allow obstruction resulting from constipation to be distinguished from obstruction resulting from another organic cause such as stenosis . adult patients having constipation as a secondary diagnosis but in combination with a primary diagnosis corresponding to one of the above - mentioned constipation - related complications were also included in the study population . as a second step , exclusion criteria were applied . because diagnoses are coded at the moment of discharge , we assumed that patients hospitalized with a principal diagnosis of constipation were likely to suffer from chronic constipation . the same assumption was made for patients who experienced one of the complications of interest , as such complications are not likely to occur in cases of acute constipation . however , as the study focused on patients with primary / idiopathic constipation , cases where constipation was likely to be directly attributable to another condition were excluded . therefore , stays during which a concomitant diagnosis ( principal or secondary ) of colorectal cancer ( icd-9 codes 153 and 154 ) , ulcerative colitis ( icd-9 code 556 ) or crohn 's disease ( icd-9 code 555 ) had been recorded were removed from the study sample . similarly , stays where a dilatation of rectum ( icd-9 code 96.22 ) or a dilatation of anal sphincter ( icd-9 code 96.23 ) was performed were also withdrawn from the sample , as these procedures were possible extraneous causes of secondary constipation . the identification of cases of possibly drug - induced ( as opposed to idiopathic ) constipation was based on the documented administration of specific drugs well described in the literature as prone to inducing constipation:710 opioids ( atc code n02a ) , calcium - antagonists ( atc c08 ) , antipsychotics ( atc n05a ) , and antidepressants ( atc n06a ) . patients receiving one of these drugs during any hospitalization over the course of the calendar year ( not necessarily related to constipation ) were assumed to be  drug - induced constipation patients . idiopathic cases were considered the main population of interest while potentially drug - induced cases were analyzed as a separate cohort . the primary study endpoints were the average cost per day and the average los in hospitalizations related to chronic idiopathic constipation . for a given stay , the hospitalization costs consist of three components : drug costs , room / bed costs , and procedure costs . room / bed costs and procedure costs were obtained by merging the data from the database with average costs per all patient refined - diagnosis related groups ( apr - drg)/severity level as calculated from the financial data files that all the belgian hospitals are legally required to send twice a year to the belgian authorities . these costs are published on the website of the ministry of public health ( latest available : data year 2008).13 costs were then extrapolated to 2011 based on the progression in costs per apr - drg as observed between 2001 and 2008 in the same published data using a geometric extrapolation . different variables reflecting the burden of the disease were also calculated as secondary endpoints : mortality during the stay , laxative drug use , and use of surgical procedures in patients with chronic idiopathic constipation . age groups taken into account in this study were adult patients below and above 65  years . the use of laxatives was tracked in the database using the atc codes as available in 2011 . the following categories of laxatives were taken into consideration : softeners and emollients ( atc a06aa ) , contact laxatives ( a06ab ) , bulk producers ( a06ac ) , osmotically acting laxatives ( a06ad ) , enemas ( a06ag ) , and glycerol ( a06x01 ) . the list of procedures of interest , established after discussions with an expert gastroenterologist , included the following items :  manual reduction of rectal prolapse ( icd-9 code 96.26 ) , proctoclysis ( icd-9 code 96.37 ) ,  removal of impacted feces ( icd-9 code 96.38 ) ,  other transanal enema ( icd-9 code 96.39 ) , and  biofeedback ( icd-9 code 94.39 ) . data were analyzed using sas software version 9 ( sas institute , cary , nc , usa ) . all unadjusted average values are reported with standard errors . given the skewed distribution , average costs average daily cost and los were also adjusted for age , gender , and other descriptive variables ( presence of a concomitant diagnosis of cancer , presence of constipation - related complications , use of constipation - related medications / treatments , and admission through emergency unit ) with multivariate regression models , using a gamma distribution and a log - link function . a total of 2694 stays with a principal diagnosis of constipation or constipation - related complication were retrieved from the belgian database for the full year 2008 , corresponding to 2615 unique patients ( one patient could have more than one stay over the course of the year ; table 1 ) . after exclusion of non - adult patients / patients with a diagnosis of colorectal cancer , ulcerative colitis or crohn 's disease documented over the course of the calendar year , the sample comprised 2101 eligible patients , corresponding to 2172 stays . among all patients with constipation , 1541 ( 73.3% ) were identified as cases of idiopathic constipation ( corresponding to 1574 stays ) , while the remaining 560 ( 26.7% ) patients had drug - induced constipation ( corresponding to 598 stays ) . thirty patients ( 1.9% ) in the main cohort had more than one constipation - related hospitalization during the study period . attrition table identifying patients included in the final study population of the eligible patients in the study cohort , 1052 ( 68.3% ) were women and 948 ( 61.2% ) were younger than 65  years . the largest subgroup was female patients younger than 65  years old , accounting for 41.8% of the eligible population . the percentage of stays corresponding to full hospitalizations was 33.5% ( table 2 ) and relevant complications were recorded in 12.8% of the stays ( n  =  202 ) , the most common being hemorrhoids ( n  =  139 ; 8.8% ) and fecal impaction ( n  =  31 ; 2.0% ) . description of study sample : number of stays with idiopathic constipation ( percentages between brackets show the proportion of stays in full hospitalization setting ) complications are identified with the icd9 codes specified between brackets . the average unadjusted estimated cost per day in hospital with a principal diagnosis of constipation / constipation - related complication was  441    4.9 in patients with idiopathic constipation ( ranging from  311    1.4 in stays in day clinic without overnight stay to  711    14.0 in full hospitalizations with complications ; table 3 ) . the average daily cost of hospitalization was significantly higher in patients with complications (  499    15.5 ) than in patients without complications (  433    5.1 ; p  <  0.001 ) . age greater than 65  years was consistently associated with higher daily costs ( p  <  0.001 ) . average daily cost ( in euros ) of hospitalization with a principal diagnosis of constipation all unadjusted values are given with se ( between brackets ) and range . costs were adjusted for gender , age category ( 2065  years / older than 65  years ) , presence of cancer diagnosis , admission through an emergency unit , and presence of a constipation - related medication / procedure documented in the patient 's data . the average unadjusted los in patients with idiopathic constipation admitted in a full hospitalization setting was 4.6 ( 0.47 ) days ( table 4 ) . the average los was significantly higher in patients experiencing complications than in patients with no recorded complications ( 7.0    2.4  days vs 4.0    0.3  days ; p  >  0.001 ) . when adjusted for age , gender , and such factors as admission through the emergency room , the presence of a codiagnosis of cancer or the use of constipation - related medications or procedures , the adjusted los was 6.1  days [ 95% ci 5.27.2 ] in patients with a complication and 4.1  days [ 95% ci 3.64.6 ] in patients without a complication . thirty percent of patients ( both full hospitalizations and visits to a day clinic ) were admitted through an emergency unit . length of stay ( los ) , percentage of admissions through emergency room ( er ) , and mortality in hospitalizations with a principal diagnosis of constipation all unadjusted values are given with standard errors ( between brackets ) and range . costs were adjusted for gender , age category ( 2065  years / older than 65  years ) , presence of cancer diagnosis , admission through an emergency unit , and presence of a constipation - related medication / procedure documented in the patient 's data . a record of laxative administration or an invasive procedure was found in 42.1% of stays ( 70.2% of full hospitalizations and 27.9% of visits to a day clinic ) . in the overall population , the most frequently used drugs were osmotically acting laxatives ( given in 36.79% of stays ) , enemas ( 16.16% of stays ) , and contact laxatives combined with osmotically acting laxatives ( 5.20% of stays ) . the most common surgical / invasive procedure was transanal enema ( 2.07% of stays ) . for all types of treatments , except proctoclysis and contact laxatives , the rate of use was higher in patients with complications than in those without ( table 5 ) . data are presented as the percentage of stays where a drug was administered or the surgical procedure performed a total of 2694 stays with a principal diagnosis of constipation or constipation - related complication were retrieved from the belgian database for the full year 2008 , corresponding to 2615 unique patients ( one patient could have more than one stay over the course of the year ; table 1 ) . after exclusion of non - adult patients / patients with a diagnosis of colorectal cancer , ulcerative colitis or crohn 's disease documented over the course of the calendar year , the sample comprised 2101 eligible patients , corresponding to 2172 stays . among all patients with constipation , 1541 ( 73.3% ) were identified as cases of idiopathic constipation ( corresponding to 1574 stays ) , while the remaining 560 ( 26.7% ) patients had drug - induced constipation ( corresponding to 598 stays ) . thirty patients ( 1.9% ) in the main cohort had more than one constipation - related hospitalization during the study period . attrition table identifying patients included in the final study population of the eligible patients in the study cohort , 1052 ( 68.3% ) were women and 948 ( 61.2% ) were younger than 65  years . the largest subgroup was female patients younger than 65  years old , accounting for 41.8% of the eligible population . the percentage of stays corresponding to full hospitalizations was 33.5% ( table 2 ) and relevant complications were recorded in 12.8% of the stays ( n  =  202 ) , the most common being hemorrhoids ( n  =  139 ; 8.8% ) and fecal impaction ( n  =  31 ; 2.0% ) . description of study sample : number of stays with idiopathic constipation ( percentages between brackets show the proportion of stays in full hospitalization setting ) complications are identified with the icd9 codes specified between brackets . the average unadjusted estimated cost per day in hospital with a principal diagnosis of constipation / constipation - related complication was  441    4.9 in patients with idiopathic constipation ( ranging from  311    1.4 in stays in day clinic without overnight stay to  711    14.0 in full hospitalizations with complications ; table 3 ) . the average daily cost of hospitalization was significantly higher in patients with complications (  499    15.5 ) than in patients without complications (  433    5.1 ; p  <  0.001 ) . age greater than 65  years was consistently associated with higher daily costs ( p  <  0.001 ) . average daily cost ( in euros ) of hospitalization with a principal diagnosis of constipation all unadjusted values are given with se ( between brackets ) and range . costs were adjusted for gender , age category ( 2065  years / older than 65  years ) , presence of cancer diagnosis , admission through an emergency unit , and presence of a constipation - related medication / procedure documented in the patient 's data . the average unadjusted los in patients with idiopathic constipation admitted in a full hospitalization setting was 4.6 ( 0.47 ) days ( table 4 ) . the average los was significantly higher in patients experiencing complications than in patients with no recorded complications ( 7.0    2.4  days vs 4.0    0.3  days ; p  >  0.001 ) . when adjusted for age , gender , and such factors as admission through the emergency room , the presence of a codiagnosis of cancer or the use of constipation - related medications or procedures , the adjusted los was 6.1  days [ 95% ci 5.27.2 ] in patients with a complication and 4.1  days [ 95% ci 3.64.6 ] in patients without a complication . thirty percent of patients ( both full hospitalizations and visits to a day clinic ) were admitted through an emergency unit . length of stay ( los ) , percentage of admissions through emergency room ( er ) , and mortality in hospitalizations with a principal diagnosis of constipation all unadjusted values are given with standard errors ( between brackets ) and range . costs were adjusted for gender , age category ( 2065  years / older than 65  years ) , presence of cancer diagnosis , admission through an emergency unit , and presence of a constipation - related medication / procedure documented in the patient 's data . a record of laxative administration or an invasive procedure was found in 42.1% of stays ( 70.2% of full hospitalizations and 27.9% of visits to a day clinic ) . in the overall population , the most frequently used drugs were osmotically acting laxatives ( given in 36.79% of stays ) , enemas ( 16.16% of stays ) , and contact laxatives combined with osmotically acting laxatives ( 5.20% of stays ) . the most common surgical / invasive procedure was transanal enema ( 2.07% of stays ) . for all types of treatments , except proctoclysis and contact laxatives , the rate of use was higher in patients with complications than in those without ( table 5 ) . data are presented as the percentage of stays where a drug was administered or the surgical procedure performed this study presents an estimation of the unadjusted average daily cost associated with a hospitalization for chronic idiopathic constipation in belgium in 2011 . it also provides an estimation of the average los associated with these hospitalizations . finally , it estimates other resource use and potential cost drivers associated with hospital admissions for chronic constipation , such as los in intensive care units , rate of admission through an emergency room , mortality , use of laxatives , and use of surgical procedures . a total of 2172 stays with constipation or a constipation - related complication as a principal diagnosis ( and no concomitant diagnosis of colorectal cancer , ulcerative colitis or crohn 's disease ) corresponding to adult patients were found in the database ; extrapolated to the whole belgian population , this would represent a total of 6388 stays over the course of the calendar year . in 598 ( 27.5% ) of these stays , one potentially constipation - inducing drug was administered and it was assumed that constipation was drug induced . projection to the total belgian population suggests that there are 4600 hospitalizations for idiopathic constipation per year in belgium . as a reference point , there are about 20  000 hospitalizations for heart failure per year.13 costs and resource use appear to be consistently higher in cases where constipation was associated with a complication . first , the los was significantly higher in patients with a constipation - related complication than in patients with no complication ( 7.0  days vs 4.0  days ) . this result was confirmed when adjusting the los for confounding factors ( adjusted los of 6.1  days [ 95% ci 5.27.2 ] in patients with a complication vs 4.1  days [ 95% ci 3.64.6 ] in patients without a complication ) . secondly , there were a higher proportion of patients being hospitalized in a full hospitalization setting ( thus requiring higher resource use ) in the population with a complication than without ( 45.5% vs 31.7% ) . finally , the average daily cost of hospitalization , adjusted for gender , age , and other confounders , was significantly higher in stays with a complication (  498 [ 95% ci 490507 ] ) than in stays without a complication (  433 [ 95% ci 428438 ] ) . the combination of these three factors resulted in an average unadjusted cost per stay that was significantly higher in patients with complications than in patients without complications (  2128 vs  1036 ; p  <  0.001 ) , thus clearly demonstrating the incremental burden of complications . cases of drug - induced constipation were not included in the main analyses as part of the cost , and resource use related to these cases may have been due to other serious underlying conditions ( e.g. cancer ) that could have explained at least part of the cost rather than the constipation itself . the list of laxative drugs and invasive procedures of interest was established based on expert opinion . however , in 57.9% of the eligible stays ( 29.8% of the full hospitalizations and 72.1% of the visits to a day clinic ) , none of these invasive procedures had been performed and none of these laxative drugs had been administered . watchful waiting was the chosen approach or that the physician did not complete all actions and only diagnostic tests were performed ( which are not collected in the database ) . also , in 12% of the stays tagged as day clinic in our analyses , the patients were admitted through an emergency unit ; it is possible that they went to the emergency room due to constipation and were sent back home with a prescription for laxative drugs . the study showed that 0.32% of patients with idiopathic constipation died during stays where constipation was recorded as the principal diagnosis ( as a comparison , the overall in - hospital mortality rate as calculated from the whole hdd , also including the most severe pathologies  during the same year was 1.56% ) . however , it was not possible to determine whether death was related to the constipation or any comorbidity or underlying indication , so these figures should be interpreted cautiously . the study was descriptive , but the main endpoints ( cost and los ) were also adjusted for possible confounders . the main limitation of this study was that it was not possible to identify cases of chronic constipation conclusively . the content of the database did not allow a strict application of the rome iii criteria ; the chronic character of constipation cases can not be established based solely on icd-9 coding . different criteria were included in the database search strategy to alleviate this limitation as much as possible . only hospital stays with a principal diagnosis of constipation or a constipation - related complication were retained ; this first criterion ensured that constipation was the main reason leading to the hospitalization , and not just a potentially acute symptom resulting from an underlying condition . stays with a concomitant diagnosis of colorectal cancer , ulcerative colitis , or crohn 's disease were excluded from the study population because these concomitant indications were assumed to be the cause of the constipation . on the other hand , some other malignancies that might result in severe constipation due to peritoneal carcinomatosis ( e.g. , gastric , ovarian or pancreatic cancers ) were not excluded as we could not identify them in the database ( no specific code for peritoneal carcinomatosis ) and might account for some of the severe cases . the study also applied a differentiation between patients hospitalized for idiopathic constipation or for drug - induced constipation ; hospital stays where opioids , calcium - antagonists , antipsychotics or antidepressants had been prescribed were assumed to relate to drug - induced constipation . however , as the database did not register dates of prescription , it was not possible to establish whether the patient was already receiving the potentially constipation - inducing drug when the diagnosis of constipation was registered , or whether the drug was prescribed later during the course of the hospitalization ( as an example , opioids can be the cause of constipation if the patient was under treatment at hospital admission , but they can also be administered during the hospitalization to relieve the pain resulting from surgery performed for a constipation - related complication ) . conversely , some patients might have been hospitalized for opioid - induced constipation but the opioid treatment could have been disrupted at the moment of the hospitalization ( and hence not recorded in the database ) ; these cases of drug - induced constipation were not identified as such . as a consequence , the criterion used for differentiation should be considered as a proxy that might be questionable in some situations . firstly , by definition , the database only contains information related to hospitalizations ( full hospitalization and day clinic ) ; conversely , it is not possible to collect data on ambulatory visits or on out of hospital drug use . as a consequence , the use of procedures that are widely performed in an ambulatory setting might be considerably underestimated . that restriction may explain the very low percentage of use observed for certain procedures ( such as biofeedback or manual disimpaction ) . secondly , while all stays related to the same patient can be tracked through a unique patient identification number attributed at the beginning of each calendar year , it is not possible to follow up patients for more than one calendar year because patients ' identification numbers are reinitialized at the beginning of each year . this should not be a drawback , however , as we calculated the average annual cost associated with a chronic condition in general and not linked to a specific episode . to benchmark this cost of chronic constipation , a comparison was made with the average cost of a hospitalization for migraine and for acute myocardial infarction ( mi ) using the same database and the same methodology ( the lack of detailed demographic information in the database did not allow for conducting a full case  control study ) . migraine ( icd-9 code 346 ) was chosen because it is a symptomatic indication , similar to idiopathic constipation and therefore a good benchmark group.14 myocardial infarction ( icd-9 code 410 ) was selected because it is a resource - intensive indication that constitutes a well referenced upper threshold when discussing hospitalization costs . an extrapolation from the hdd showed that the number of patients hospitalized in 2008 for mi or migraine was 19  000 and 2500 , respectively . the average cost of a full hospitalization for mi and migraine was  6698    118.9 and  2027    88.5 , respectively , whereas it was  2891    257 for a full hospitalization for chronic idiopathic constipation . it might be argued that most constipated patients would be treated in ambulatory setting and that hospitalization costs only represent a marginal portion of the economic burden of constipation . according to an american case control study following a cohort of 168 women suffering from chronic constipation and comparing it with a matched control group ( n  =  336 ) over a 15-year period,15 the average number of visits to hospital ( including inpatient visits , outpatient visits , and admission through emergency unit ) was 0.54 visits per patient - year in the case group vs 0.36 visits per patient - year in the control group . the difference ( 0.18 visits to hospital per patient - year ) can be used as a proxy to estimate the incremental rate of hospitalizations due to chronic constipation . this estimate is consistent with the rates provided by a european study , showing an incremental rate of hospitalization attributable to chronic constipation equal to 0.44 and 0.32 visits / patient - year in a population of patients with constipation - predominant ibs in france and the united kingdom , respectively.16 this confirms the fact that most of the constipation patients would seek treatment in an ambulatory setting and be treated for instance with laxatives available as over - the - counter drugs . however , the higher proportion of constipation patients treated in ambulatory setting is compensated by the low cost related to these patients as compared with hospitalized patients ; caekelbergh et  al . ( 2009 ) estimated that the cost of an episode of constipation related to opioid use treated in ambulatory setting in belgium was  130 ( 95% ci : 108153 ) , including the cost of laxatives that are not reimbursed by the belgian public health care payer.17 as a consequence , hospitalization costs remain an important component of the economic burden of constipation , despite the relatively low rate of hospitalization . ims heor , employer of pc and ml , has received consulting fees to conduct the research that resulted in this manuscript . pc and ml contributed to study conception and design , data analysis , and interpretation of the results ; aj and dd contributed to study conception and interpretation of the results ; gb contributed to interpretation of the results . all authors were involved throughout the development of the manuscript and approved the final version .
backgroundreal - life data on the economic burden of chronic idiopathic constipation are scarce 
 . the objectives of this study were to assess hospitalization resource use and costs associated with chronic constipation and its complications in belgium.methodsthis was a single country , retrospective study using the ims hospital disease database ( 2008 ) , which comprises data on 34% of acute hospital beds in belgium and contains information on patient demographics , length of stay ( los ) , billed costs , drug use , diagnoses , and procedures 
 . stays with a primary diagnosis of constipation , or a secondary diagnosis of constipation and a concomitant diagnosis of a constipation - related complication , were selected . 
 patients with diagnoses of colorectal cancer , ulcerative colitis or crohn 's disease , or who had stays involving potentially constipation - inducing procedures , were excluded as having secondary constipation . 
 patients receiving opioids , calcium - antagonists , antipsychotics or antidepressants were excluded as having drug - induced constipation.key resultsin total , 1541 eligible patients were identified . 
 the average unadjusted cost per day in hospital for idiopathic constipation was  441 (  311    1.4 in day clinic visits without overnight stays ;  711    14.0 in full hospitalizations with complications ) . 
 the average los in a full hospitalization setting was 7.0 and 4.0  days in stays with and without complications , respectively . 
 the most frequent drug and procedural treatments were osmotically acting laxatives ( with complications : 42.61% ; without complications : 35.69% ) , and transanal enema ( 2.32% and 2.03% ) , respectively.conclusions & inferencesthe burden of constipation is often underestimated ; it is a condition reflected by hospital - related costs comparable to such indications as migraine , which increase when associated with complications .