Prevalence of irritable bowel syndrome in Southeast Hungary: Impact of Rome III and Rome IV criteria

Abstract

BACKGROUND

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder, posing a substantial burden on healthcare systems and significantly impairing the quality of life. Despite its clinical relevance, no population-based data on IBS prevalence have been available from Hungary.

AIM

To investigate the prevalence of IBS in Southeast Hungary using Rome III and IV criteria in voluntary blood donors and patients with psychiatric disorders.

METHODS

A cross-sectional survey was conducted among voluntary blood donors and outpatients with psychiatric disorders. Participants completed validated questionnaires based on Rome III and IV criteria. A single instrument was employed. Demographic data, psychiatric comorbidities, and the presence of chronic somatic diseases were also documented. Statistical analyses compared prevalence estimates across diagnostic frameworks and populations.

RESULTS

Applying the Rome III criteria led to a substantially higher IBS prevalence than when applying Rome IV. Among blood donors, prevalence decreased from 7.6% (Rome III) to 0.7% (Rome IV), whereas among patients with psychiatric disorders, it decreased from 15.4% to 5.0%. Patients with psychiatric disorders consistently demonstrated higher prevalence rates than blood donors, with a marked female predominance. The presence of chronic diseases did not significantly affect IBS prevalence; however, a trend toward higher rates was observed, suggesting that comorbidities can be more strongly associated with upper gastrointestinal hypomotility than with IBS itself.

CONCLUSION

The choice of diagnostic criteria influences IBS prevalence and affects high- and low-risk populations differently. These insights underscore the significance of integrated multidisciplinary approaches to functional gastrointestinal disorders.

Key Words: Irritable bowel syndrome; Rome criteria; Prevalence; Psychiatric comorbidity; Functional gastrointestinal disorders; Hungary

Core Tip: This study reveals how diagnostic criteria and population context significantly influence irritable bowel syndrome prevalence estimates. The Rome IV criteria yield lower rates than Rome III, and psychiatric comorbidity significantly increases disease burden. Although chronic illnesses demonstrate limited impact, trends suggest a role for gut-brain axis dysregulation. These findings emphasize the significance of integrated care and nuanced epidemiological approaches to functional gastrointestinal disorders.

INTRODUCTION

Irritable bowel syndrome (IBS) represents one of the most prevalent disorders of gut-brain interaction, characterized by chronic abdominal pain associated with altered bowel habits in the absence of detectable structural abnormalities. Its global epidemiology has been extensively investigated; however, prevalence estimates substantially differ depending on the diagnostic criteria applied. The Rome criteria, developed for standardizing diagnosis, have undergone several revisions, with the most recent iteration, Rome IV, published in 2016, introducing more restrictive symptom definitions than Rome III[1,2].

A comprehensive meta-analysis revealed that the pooled global prevalence of IBS using the Rome III criteria was approximately 9.2% (95%CI: 7.6%-10.8%), whereas applying the Rome IV criteria yielded a markedly lower prevalence of 3.8% (95%CI: 3.1%-4.5%)[1,2]. This reduction is consistent across multiple geographic regions and is attributed to stricter symptom frequency thresholds and excluding “discomfort” from the core diagnostic definition. The Rome Foundation Global Study further confirmed this trend, reporting a 10.1% prevalence with Rome III vs 3.8% with Rome IV in countries where both criteria were applied[3].

Beyond prevalence, IBS is associated with a substantial burden of chronic comorbidities. Population-based studies have identified frequent co-occurrence with other functional pain syndromes and psychiatric comorbidities[4-7].

Considering these factors, studies that directly compare IBS prevalence under both Rome III and IV criteria within distinct populations, particularly healthy individuals and those with established psychiatric disorders, are critically needed. No data exist on how IBS prevalence in other non-average populations changes following the introduction of Rome IV criteria. Furthermore, how the presence of comorbidities and other factors influence this prevalence remains unknown. Finally, whether this decrease is beneficial for the criteria[8].

This study aimed to assess IBS prevalence in Southeast Hungary using both Rome III and IV diagnostic criteria, focusing on two distinct populations: Voluntary blood donors and patients diagnosed with psychiatric disorders. Considering the paucity of population-based data on IBS prevalence in Hungary, this study sought to provide novel insights into how diagnostic criteria impact prevalence estimates and explore the potential disparity between a presumed low-risk group (blood donors) and a high-risk group (patients with psychiatric disorders). The significance of research on functional disorders can also be attributed to their high burden on the healthcare system, as their prevalence is extremely high and can significantly affect the quality of life[9].

MATERIALS AND METHODS

This study was conducted during blood donations organized by the Hungarian National Blood Transfusion Service, Szeged Regional Blood Supply Centre, which took place at the blood donation station in Szeged and at external sites. The exclusion criteria for blood donation are summarized in Table 1.

Table 1 Exclusion criteria of voluntary blood donors.

Exclusion criteria of voluntary blood donation
Any virus carrier status, any ongoing acute infection, any malignant disease, blood coagulation and other hematological disorders, epilepsy, Parkinson’s disease, rheumatic heart disease, systemic autoimmune diseases, Graves’ disease, chronic kidney disease, pancreatic disease, liver enlargement, heart surgery, any transplantation
Hypertension	Started or modified therapy within 1 month; severe, inadequate hypertension.
Blood pressure	< 100 mmHg or > 180 mmHg systolic or > 100 mmHg diastolic
Hypothyreosis	Within 180 days from recovery of infection, medicine-induced or traumatic thyroid disease
Hashimoto thyreoiditis	Symptomatic, therapy shorter than 3 months, taking corticosteroids
Bronchial asthma	Symptomatic or uncontrolled
Type 2 diabetes mellitus	Insulin use
Disc herniation	Sciatica within 30 days
Osteoporosis	Severe osteoporosis
Tachycardia/arrhythmia	< 50 bpm or >100 bpm, irregular rhythm for 7 days, presence of murmur
Celiac disease	Symptomatic

Patients with psychiatric disorders were enrolled on the basis of their International Classification of Diseases-10 diagnosis and interwieved in the Outpatient Department of the Psychiatric Care Center of Pándy Kálmán Békés County Hospital in Gyula and Réthy Pál Hospital in Békéscsaba. Data were collected from blood donors and patients with psychiatric disorders using questionnaires established by the Gastrointestinal Motility Workgroup, Department of Internal Medicine, University of Szeged, based on the Rome Foundation internationally accepted criteria[10,11] adopted for both Rome III and IV classification systems.

The prevalence, intensity, onset, and duration of typical IBS symptoms were assessed. Moreover, medical history data relevant to the disease, including previous gastrointestinal infections, abdominal surgeries, treatment for psychiatric disorders (anxiety and depression), and the quality of life of the patients, were investigated. The nature of the stool was investigated using the Bristol scale. General, demographic, and social data were collected, in addition to the specific questions. The quality of life was rated using the Visual Analog Scale, with 0 representing the worst and 100 indicating the best. An interviewer assisted the study participants in completing the survey.

Statistical analyses were performed using the R program, and a P value of 0.05 was considered statistically significant.

The study was approved by the institutional review board of University of Szeged.

RESULTS

In the first part of our study, 1239 healthy blood donor volunteers were enrolled. Among them, 699 were male, and 540 were female. The mean age of the participants was 39 (17-66) years, and their mean body mass index was 26.9 (17-52.5) kg/m².

Regarding other factors, 56 (4.5%) participants exhibited an abnormal stool frequency. Of them, 47 (3.8%) reported chronic constipation (≤ 3 stools/week), 9 (0.7%) diarrhea (≥ 3 stools/day), and 94 (7.6%) either of the two. The remaining participants (1055/1239, 85.1%) defecated once daily.

The blood donors were classified into the Rome III and IV groups according to the diagnostic criteria based on the previously and currently used expert consensus. No statistical differences were observed in the demographic characteristics between the two groups. Overall, 94 (7.6%) participants presented with IBS based on the Rome III criteria. However, only 9 (0.73%) participants met the latest Rome IV criteria. As further statistical analysis of the latter result could not be performed, the characteristics of the IBS-positive and IBS-negative groups were compared on the basis of the previous Rome III criteria, which had long been considered valid. The participants with IBS based on the Rome III criteria generally demonstrated a significantly decreased quality of life compared with IBS-negative participants.

As approximately one-fifth of the study population had at least one chronic disease that does not disqualify them from blood donation, the difference in the prevalence of IBS between this group and those who declared themselves completely healthy was determined. Although the proportion was slightly higher in participants with chronic diseases (25/261, 9.6%) than in those without (69/978, 7.1%), the results did not significantly differ (P = 0.1714). Thus, we continued to work with the whole population.

The following were the IBS subtypes according to the Rome III criteria: (1) IBS-C [Bristol Stool Scale (BSS), 1-2], n = 12 (12.8%); (2) IBS-D (BSS, 6-7), n = 3 (3.2%); and (3) IBS-M, n = 79 (84%). As the small number of IBS-D and IBS-C cases restricted further analysis, the IBS-positive patients were generally investigated. The results are presented in Table 2.

Table 2 General statistical data of the categorical variables, mean ± SD/n (%).

Demographic data	Control (n = 1145)	Irritable bowel syndrome (n = 94)	P value
Age (years)	39.14 ± 12.41	37.83 ± 11.78	0.3236
Body mass index	27.12 ± 4.85	27.62 ± 5.07	0.3385
Quality of life	80.95 ± 14.39	75.37 ± 17.99	0.0004
Household population
Alone	125 (10.9)	7 (7.4)	0.5559
Adults only	442 (38.6)	39 (41.5)
Adults and children	578 (50.5)	48 (51.1)
Residence
Urban	750 (65.5)	68 (72.3)	0.1784
Rural	395 (34.5)	26 (27.7)
Childhood residence
Urban	672 (58.7)	62 (66.0)	0.1681
Rural	473 (41.3)	32 (34.0)
Occupation
Student	153 (13.3)	14 (14.9)	0.0006
Intellectual	509 (44.5)	59 (62.8)
Physical	483 (42.2)	21 (22.3)
Smoking
Smoker	282 (24.6)	22 (23.4)	0.8976
Non-smoker	699 (61.1)	57 (60.6)
Former smoker	164 (14.3)	15 (16.0)
Coffee consumption
More than 1	519 (45.3)	46 (48.9)	0.7816
1/day	270 (23.6)	20 (21.3)
Never	356 (31.1)	28 (29.8)
Alcohol consumption
Regular	45 (3.9)	3 (3.2)	0.3438
Occasional	848 (74.1)	76 (80.8)
Never	252 (22.0)	15 (16.0)

In the control group, females demonstrated a significantly higher IBS prevalence than males. An analysis employing sex as a risk factor for IBS revealed that females were 1.8-fold at risk compared with males, indicating a statistically significant difference (P = 0.016).

In addition, a significantly high proportion of intellectual workers with IBS according to the Rome III criteria was observed. Meanwhile, the proportion of physical workers was significantly low (χ² = 14.91, P = 0.0006). For the latter, the risk was 0.40-fold (odds ratio = 0.40; 95%CI: 0.17-0.97; P = 0.043). Therefore, being a physical worker could serve as a protective factor for IBS development.

Overall, of the three symptoms that are the main criteria for diagnosis (abdominal pain, bloating, and abdominal distension), bloating was the most frequently reported (92/94, 98%). Abdominal distension was documented in approximately 50% of the cases (48/94, 51%), and only 12 (12.8%) participants exhibited abdominal pain.

In the other part of our study, 695 patients diagnosed with psychiatric disorders were interviewed. Among them, 159 were male, and 536 were female. The average age of the participants was 62.3 (24-95) years, and their mean body mass index was 28.3 (13.8-66.6) kg/m². Overall, 212 (29.3%), 393 (54.3%), and 118 (16.4%) participants lived alone, lived with their family with adults only, and lived with their family with children, respectively. According to the place of residence, three (0.4%), 483 (66.8%), 223 (30.9%), and 14 (1.9%) participants lived in the capital city, other cities/towns, villages, and farms, respectively. Of the respondents who completed the questionnaire, 6 (0.8%), 300 (41.9%), 386 (53.3%), and 31 (4%) grew up in the capital city, other cities/towns, villages, and farms, respectively.

Among the respondents, excluding those with psychiatric disorders, hypertension was the most common chronic disease. We compared the prevalence of chronic diseases between patients with psychiatric disorders and blood donors, stratified by IBS status. In both investigated populations, the presence of chronic diseases did not constitute a statistical difference between the IBS groups defined using the Rome III and IV criteria; nevertheless, a discernible trend can still be observed (Tables 3 and 4).

Table 3 Comparison of prevalence of chronic illnesses in blood donors with and without irritable bowel syndrome based on Rome III and IV criteria, n (%).

Item		Blood donors (n = 1239)		P value
		With chronic illness	Without chronic illness
Rome III	Patients with IBS	25 (9.6)	69 (7.1)	0.1714
	Patients without IBS	236 (90.4)	909 (92.9)
Rome IV	Patients with IBS	3 (1.1)	6 (0.6)	0.4080
	Patients without IBS	258 (98.9)	972 (99.4)

IBS: Irritable bowel syndrome.

Table 4 Comparison of prevalence of chronic illnesses in patients with psychiatric diseases with irritable bowel syndrome based on Rome III and IV criteria, n (%).

Item		Patients with psychiatric diseases (n = 695)		P value
		With chronic illness	Without chronic illness
Rome III	Patients with IBS	82 (16.8)	25 (12.1)	0.1144
	Patients without IBS	406 (83.2)	182 (87.9)
Rome IV	Patients with IBS	29 (5.9)	6 (2.9)	0.0933
	Patients without IBS	459 (94.1)	201 (97.1)

IBS: Irritable bowel syndrome.

Using abdominal complaints for diagnosing IBS, 152 of the 723 volunteers (27.0%) exhibited at least one abdominal complaint (abdominal pain ± bloating ± abdominal distension). Of them, 39 (6.9%), 19 (3.4%), and 126 (16.7%) presented with some type of abdominal pain, abdominal distension, and bloating, respectively.

Regarding the other diagnostic cornerstone of altered fecal habits, 77 (13.7%) participants had an abnormal stool frequency, 52 (9.3%) and 25 (4.5%) of whom reported chronic constipation (≤ 3 stools/week) and diarrhea (≥ 3 stools/day), respectively. Furthermore, of the participants, 12.8% (n = 72) and 132 (23.5%) complained of stools with mucus and insufficient emptying sensation, respectively.

The following was the IBS subgroup distribution according to the Rome III criteria: (1) IBS-C (BSS, 1-2), n = 10 (12.3%); (2) IBS-D (BSS, 6-7), n = 17 (21%); (3) IBS-U, n = 54 (66.7%); and (4) IBS-M, n = 0. Based on the Rome IV criteria, the IBS subgroup distribution was as follows: (1) IBS-C (BSS, 1-2), n = 2 (8%); (2) IBS-D (BSS, 6-7), n = 12 (48%); (3) IBS-U, n = 11 (44%); and (4) IBS-M, n = 0. Owing to the limited number of cases in the IBS-C and IBS-D groups, further subgroup analysis could not be performed.

A female predominance was noted among patients with psychiatric disorders; however, the IBS group exhibited an even greater female predominance than the control group (χ² = 5.653, P = 0.0174).

The patients were classified according to their psychiatric disorder, and IBS prevalence in the resulting groups was assessed in Table 5.

Table 5 Prevalence of different psychiatric diseases in patients with irritable bowel syndrome based on Rome III and IV criteria, n (%).

P = 0.96	IBS (Rome III)	IBS (Rome IV)
Depression	20 (18.7)	6 (17.1)
Anxiety	10 (9.3)	3 (8.6)
Both	67 (62.7)	24 (68.6)
Neither	10 (9.3)	2 (5.7)

IBS: Irritable bowel syndrome.

Patients with psychiatric disorders showed consistently higher IBS prevalence than blood donors, regardless of the diagnostic criteria employed. The Rome IV criteria yielded lower prevalence rates across all groups than Rome III. Patients with psychiatric disorders, especially those with both depression and anxiety, demonstrated a significantly higher IBS prevalence than blood donors. The shift from Rome III to Rome IV criteria markedly decreased the proportion of diagnosed cases, underscoring the influence of diagnostic definitions on prevalence estimates (Table 6). Age is a nuanced factor, although not a linear one. In both investigated populations, we observed no statistical differences in IBS prevalence across those aged < 30 years, 30-50 years, and > 50 years, based on either the Rome III (P = 0.425 and P = 0.379) or Rome IV diagnostic criteria (P = 0.676 and P = 0.107).

Table 6 Irritable bowel syndrome prevalence in blood donors and psychiatric patients, n (%)/mean (minimum-maximum)/mean ± SD (minimum-maximum).

Item	Blood donors (n = 1239)	Psychiatric patients (n = 695)	Patients with psychiatric diseases (n = 695)
			Depression (n = 136)	Anxiety (n = 69)	Both (n = 408)	Neither (n = 82)
IBS Rome III	94 (7.6)	107 (15.4)	20 (14.7)	10 (14.5)	67 (16.4)	10 (12.2)
IBS Rome IV	9 (0.7)	35 (5.0)	7 (5.1)	3 (4.4)	24 (5.9)	1 (1.2)
Males	699 (56.4)	159 (22.9)	26 (19.1)	17 (24.6)	91 (22.3)	25 (30.5)
Females	540 (43.6)	536 (77.1)	110 (80.9)	52 (75.4)	317 (77.7)	57 (69.5)
Age	39 (17-66)	62.3 ± 13.1 (24-95)	62.0 ± 12.4 (24-90)	57.9 ± 14.8 (24-81)	63.9 ± 12.4 (26-95)	58.1 ± 14.8 (30-82)

IBS: Irritable bowel syndrome.

DISCUSSION

This study represents the first attempt to assess IBS prevalence in Southeast Hungary using the Rome III and IV diagnostic criteria across two distinct populations: (1) Voluntary blood donors; and (2) Patients with psychiatric disorders. Our findings confirm the considerable impact of diagnostic definitions on prevalence estimates and underscore the significance of considering comorbidities and psychosocial factors in IBS epidemiology.

Consistent with global data, applying the Rome III criteria caused a markedly higher IBS prevalence than when applying the more restrictive Rome IV definition. Large-scale international studies have repeatedly demonstrated this discrepancy. The Rome Foundation Global Epidemiology Study, involving over 73000 participants from 33 countries, reported a 10.1% prevalence using Rome III vs only 4.1% with Rome IV, highlighting the more stringent nature of Rome IV and its tendency to capture patients with more severe disease and higher psychosocial burden[12]. Similarly, a recent synthesis of epidemiological data has confirmed that Rome IV prevalence estimates are approximately 50% those obtained using Rome III, with global pooled prevalence rates of 3.8% and 9%-11%[13]. These findings align with our data from Hungary. Differences between the investigated participants may account for the variances between the reported prevalences globally and in Hungary. We aimed to select a “healthy” population as a control group. Blood donors are considered to be “healthier” than the general population, as they have to meet certain blood donation criteria. Based on the results of a global study, in the general population, the reduction rate was approximately one-third (from 10.1% to 3.8%), and we observed a 90% decrease in our population, which is considered healthier than the general population. This finding suggests that the introduction of the Rome IV criteria eliminated the false-positive IBS cases.

The comparison between blood donors and patients with psychiatric disorders further emphasizes the role of psychological comorbidity. Patients with psychiatric disorders demonstrated a significantly higher IBS prevalence, irrespective of diagnostic framework. This finding is frequently explained by changes in pain transmission and the potential involvement of large-scale brain circuits, as IBS is classified as nociplastic pain in the pain mechanism classification. Our observation aligns with recent evidence highlighting strong associations between IBS and psychiatric disorders, particularly anxiety and depression. A bibliometric analysis of over 2500 publications underscored the growing recognition of the gut-brain axis, with approximately 40% of patients with IBS presenting with anxiety and 29% with depressive symptoms[14]. More recent clinical data from Middle Eastern populations also confirmed that psychological distress represents a major determinant of IBS prevalence, with psychiatric symptoms independently increasing the likelihood of IBS[15]. These findings reinforce the significance of integrated care models addressing gastrointestinal and psychiatric symptoms.

The role of chronic somatic diseases in IBS prevalence remains complex. Although our study did not reveal statistical differences, individuals with chronic illnesses exhibited a consistent trend toward a higher prevalence. This finding aligns with a study from Hungary investigating reflux-related symptoms among blood donors, reporting frequent overlap between functional gastrointestinal complaints and chronic conditions[16]. In patients with reflux-related symptoms, the presence of chronic diseases has previously been demonstrated to heighten the prevalence of such symptoms; however, this association was not clearly confirmed in our current investigation, although the results indicated a suggestive trend. The sample size of the investigated population may account for this discrepancy. These findings suggest that comorbidities are more strongly associated with upper gastrointestinal hypomotility[17-19]. International studies further support this observation. Recent reviews have revealed that IBS is frequently accompanied by multimorbidity, including gastroesophageal reflux disease, functional dyspepsia, metabolic disorders, and psychiatric comorbidities[20]. Moreover, mechanistic studies have suggested that shared pathways, including microbiome alterations, immune activation, and dysregulated serotonin metabolism, can underlie the frequent co-occurrence of IBS with depression and other chronic conditions[21]. These findings highlight the significance of considering multimorbidity in clinical management and epidemiological research.

From a public health viewpoint, the high IBS prevalence among patients with psychiatric disorders emphasizes the significance of prompt recognition and multidisciplinary management. The discrepancy between Rome III and IV prevalence estimates raises crucial methodological and clinical questions: Although the Rome IV criteria improve diagnostic specificity, they may exclude patients who nonetheless experience significant symptom burden and impaired quality of life. Recent prospective cohort data from Norway demonstrated that even among patients with inflammatory bowel disease in remission, Rome IV-defined IBS-like symptoms were noted in 16%-22% of cases and were strongly associated with fatigue, female sex, and reduced quality of life[22]. This finding suggests that the Rome IV criteria can capture a subgroup with particularly severe disease but at the cost of underestimating the broader population burden.

Limitations and future directions

Our study was limited by its cross-sectional design and reliance on self-reported questionnaires, potentially introducing recall bias. The relatively small number of Rome IV-positive cases also restricted subgroup analyses. Subsequently, performing meaningful subgroup analysis for IBS-C and IBS-D was not possible. During questionnaire completion, patients with psychiatric disorders may have been medicated, which had an effect on bowel movements, likely impacting the prevalence values of different IBS subtypes. Future research should confirm these findings in larger population-based cohorts and explore longitudinal trajectories of IBS in relation to psychiatric morbidity and chronic disease burden. Integrating biological markers, including microbiome or metabolomic profiling, may also help disentangle the shared mechanisms underlying IBS and its comorbidities.

CONCLUSION

This study offers the first comparative data on IBS prevalence in Southeast Hungary, underscoring the profound influence of diagnostic criteria and the significance of population context. The marked discrepancy between Rome III and IV prevalence estimates aligns with global results, emphasizing the methodological challenges in assessing functional gastrointestinal disorders. The consistently higher prevalence among patients with psychiatric disorders highlights the role of psychosocial comorbidity in influencing disease burden. Although chronic diseases did not significantly affect IBS prevalence in our cohorts, the healthiest population demonstrated the smallest value. This trend suggests that multimorbidity can still contribute to symptom expression, potentially through mechanisms, such as gut-brain axis dysregulation and chronic psychosocial stress. Psychiatric comorbidity seems to be a major risk factor irrespective of the criteria.

Collectively, these findings reinforce the significance of nuanced interpretation of prevalence data, careful consideration of diagnostic frameworks, and integrated clinical approaches addressing psychological and somatic comorbidities. The choice of criteria has profound effects on estimated disease burden, which should be considered in health policy planning. This study contributes novel insights into IBS epidemiology and underscores the necessity of continued research into the complex interplay between diagnostic criteria, comorbidity, and patient quality of life by situating Hungary-based data within the broader international context.

ACKNOWLEDGEMENTS

The authors thank Lenke Bálint and the staff of the Departement of Psychiatry of Pándy Kálmán Hospital in Békés County.