Increased psychological distress and somatization in patients with irritable bowel syndrome compared with functional diarrhea or functional constipation, based on Rome IV criteria

Innovations in the diagnosis, treatment, and management of disorders of gut-brain interaction (DGBI)

INTRODUCTION

Functional dyspepsia (FD) and irritable bowel syndrome (IBS) are the most prevalent disorders of gut-brain interaction (DGBI), frequently overlapping and associated with complex pathophysiological mechanisms. Increasing evidence implicates gut microbiota alterations in driving symptoms via immune activation, altered motility, gut vascular barrier and gut-brain axis disruption.

AREAS COVERED

This review explores the role of gut microbiota in FD and IBS pathogenesis and symptomatology. A comprehensive literature search was conducted using PubMed, EMBASE, and Google Scholar databases, including studies published between January 2013 and March 2025. Particular focus is given to microbiota-targeted therapies such as prebiotics, probiotics, synbiotics, postbiotics, and fecal microbiota transplantation (FMT). The review also discusses multidimensional treatment strategies combining dietary and lifestyle modification, cognitive-behavioral therapy, and pharmacological neuromodulation. Recent advances in diagnostic methods, including capsule-based microbiota sampling and digital tools for remote psychogastroenterology care, are highlighted.

EXPERT OPINION

Despite scientific progress, current DGBI management remains insufficiently personalized. Future approaches should integrate individualized microbiota profiling with targeted interventions and utilize innovative diagnostic and digital health technologies to enhance clinical outcomes in FD and IBS.

Rome Foundation Working Team Report on overlap in disorders of gut-brain interaction

In patients with disorders of gut-brain interaction (DGBI), overlapping non-gastrointestinal conditions such as fibromyalgia, headaches, gynaecological and urological conditions, sleep disturbances and fatigue are common, as is overlap among DGBI in different regions of the gastrointestinal tract. These overlaps strongly influence patient management and outcome. Shared pathophysiology could explain this scenario, but details are not fully understood. This overlap has been shown to be of great relevance for DGBI. In addition, symptoms considered to be caused by a DGBI could have a detectable organic cause, and in patients with a diagnosed organic gastrointestinal disease, symptoms not clearly explained by the pathology defining this organic disease are common. Thus, the aims of this Rome Foundation Working Team Report were to review the literature on overlapping conditions among patients with paediatric and adult DGBI and, based on the available epidemiological and clinical evidence, make recommendations for the current diagnostic and therapeutic approach, and for future research. Specifically, we focused on other DGBI in the same or different gastrointestinal anatomical region(s), DGBI overlap with organic bowel diseases in remission, and DGBI overlap with non-gastrointestinal, non-structural conditions.

Psychopathology and the Validity of Gastrointestinal Symptom Reporting as Revealed Through Cluster Analyses of MMPI-2-RF Results

BACKGROUND

Psychological state, self-reported gut symptoms, and somatic complaints are recognized relationships that can impact health assessment and subsequent treatment.

AIM

To investigate the impact of psychological state and personality on symptom self-reporting and somatization.

METHODS

Sixty-two (62) participants from the Hunter region of NSW (Australia) undertook a survey of health and lifestyle along with an MMPI-2-RF assessment of personality, psychopathology, and test-taking attitude. Participants also completed the Rome Criteria to assess functional gastrointestinal disorders (FGIDs). To assist the interpretation of MMPI-2-RF results, clustering was applied to identify similar responses and sub-cohort profiles of reporting.

RESULTS

Cluster analysis revealed four sub-cohorts, stratified by psychopathology, gut-related symptoms, and the validity of self-reported somatic complaints. Sample clustering identified one sub-cohort defined by high rates of negative affectivity and suicidal ideation. Apart from these differences, clusters were uniform for age, sex, smoking, mental health diagnoses, as well as for gut-related conditions.

CONCLUSION

Results provide further evidence of the interaction of the gut-brain axis and its relationship to serious mental health conditions. It also points to the need to assess the veracity of self-reported symptomatology that may be both pathognomonic for psychopathology but might also be a consequence of gut dysbiosis. Clustering assisted these investigations by defining distinct sub-cohorts based on participant MMPI-2-RF responses.

Predictors of Symptoms Trajectories in Newly Diagnosed Ulcerative Colitis: A 3-Year Follow-up Cohort Study

BACKGROUND AND AIMS

Psychological symptoms are associated with poorer ulcerative colitis [UC]-related outcomes. However, the majority of research is cross-sectional. We aimed to identify subgroups based on the longitudinal evolution of GI symptom levels and health-related quality of life [HRQoL], and to disentangle the directionality of effects between GI symptom levels and psychological distress.

METHODS

Self-reported gastrointestinal [GI] symptom severity, HRQoL, inflammatory biomarkers, and psychological distress were assessed in 98 newly diagnosed UC patients at disease onset and yearly for 3 consecutive years. Latent class growth analysis was used to determine subgroups based on longitudinal trajectories of symptom severity and HRQoL, and baseline predictors of trajectory group membership were determined. Cross-lagged structural equation models were used to disentangle temporal relationships between psychological functioning and symptom severity.

RESULTS

Patients with higher initial psychological distress had increased probability of maintaining higher levels of diarrhoea and abdominal pain. Conversely, patients with lower initial levels of diarrhoea and abdominal pain had higher chances of maintaining lower levels of psychological distress. Higher levels of C-reactive protein at baseline predicted greater improvements in mental health after anti-inflammatory treatment. Reductions in diarrhoea and abdominal pain preceded reductions in psychological symptoms over time.

CONCLUSIONS

Baseline psychological distress is predictive of increased GI symptom severity and reduced mental HRQoL over time, suggesting early assessment of psychological symptoms may identify patients who may have worse disease trajectories. Abdominal pain predicted increased psychological distress, but not the other way around. Intervening on abdominal pain may help prevent or reduce future psychological distress.

Natural History and Outcomes of Individuals With Functional Bowel Disorder: A 9-year Population-Based Longitudinal Study

INTRODUCTION

Long-term studies characterizing the natural history of functional bowel disorder (FBD) from community-based settings and exploring association with psychological factors are sparse. We aimed to evaluate the evolution of symptoms, health outcomes, and association of FBD with psychological disorders in Chinese population.

METHODS

Individuals identified from random sampling of residents of Hangzhou, China, participated in a baseline survey in January 2010. Follow-up phone survey was conducted in December 2018. FBD was diagnosed based on Rome III criteria.

RESULTS

Among 452 individuals (mean age 44.6 ± 15.3 years, 174 [38%] male) who completed the study, the prevalence of FBD was 36.3% (95% confidence interval [CI] 32.6-40.0%) at enrollment and 36.1% (95% CI 32.3-39.8%) at follow-up survey ( P = 0.94). However, 214 individuals (47%) had interval change in diagnosis. Although no difference in incidence of organic disease or death was observed, a higher proportion of patients with FBD (16/164, 9.8% vs 9/288, 3.1%; P = 0.003) compared with those without FBD received non-cancer-related abdominal and/or pelvic surgery during follow-up. FBD was associated with anxiety and/or depression at initial (adjusted odds ratio [AOR] = 1.7, 95% CI 1.7-2.7, P = 0.02) and follow-up (AOR = 8.0, 95% CI 3.2-20.0, P < 0.001) surveys. Diagnosis of FBD at baseline was associated with new-onset anxiety and/or depression at follow-up (AOR = 3.2, 95% CI 1.2-8.3, P = 0.01).

DISCUSSION

Although the prevalence of FBD remained stable, transformation of symptoms was common over time. Patients with FBD may have increased risk of receiving non-cancer-related abdominal and/or pelvic surgery. FBD symptoms at baseline increased the risk of new-onset anxiety and/or depression by 3.2-fold over the next 9 years.

Latent profile analysis reveals the central role of psychological symptoms in driving disease severity in chronic constipation

BACKGROUND

Chronic constipation (CC) is defined by symptom criteria reflecting heterogenous physiology. However, many patients with CC have significant psychological comorbidities-an alternative definition using a biopsychosocial classification model could be warranted to inform future treatments. We sought to: (1) empirically derive psychological symptom profiles of patients with CC using latent profile analysis and (2) validate these profiles by comparing them on symptom severity, GI-specific anxiety, body mass index (BMI), and anorectal manometry findings.

METHODS

Participants included adults presenting for anorectal manometry for CC (N = 468, 82% female, Mage = 47). Depression/anxiety symptoms and eating disorder (ED) symptoms (EAT-26) were used as indicators (i.e., variables used to derive profiles) representing unique psychological constructs. Constipation symptoms, GI-specific anxiety, BMI, and anorectal manometry results were used as validators (i.e., variables used to examine the clinical utility of the resulting profiles).

KEY RESULTS

A 5-profile solution provided the best statistical fit, comprising the following latent profiles (LPs): LP1 termed "high dieting, low bulimia;" LP2 termed "high ED symptoms;" LP3 termed "moderate ED symptoms;" LP4 termed "high anxiety and depression, low ED symptoms;" and LP5 termed "low psychological symptoms." The low psychological symptom profile (61% of the sample) had lower abdominal and overall constipation severity and lower GI-specific anxiety compared to the four profiles characterized by higher psychological symptoms (of any type). Profiles did not significantly differ on BMI or anorectal manometry results.

CONCLUSIONS AND INFERENCES

Profiles with high psychological symptoms had increased constipation symptom severity and GI-specific anxiety in adults with CC. Future research should test whether these profiles predict differential treatment outcomes.

Psychological distress and coping efficacy in children with disorders of gut-brain interaction

BACKGROUND

Multiple psychological factors influence disorders of gut-brain interaction (DGBIs). We aimed to evaluate psychological distress in Colombian schoolchildren with and without DGBIs.

METHODS

We included children ages 8-18 years without organic medical conditions from largest regional public schools in Colombia. Children completed Spanish versions of Rome III diagnostic questionnaire for DGBIs, State Trait Anxiety Inventory for Children (STAIC), Children's Somatization Inventory (CSI), and a measure of coping efficacy. These data, demographic and socioeconomic characteristics, were compared between children with DGBIs and healthy peers. Exploratory analyses investigated differences between youth with symptoms of functional abdominal pain disorders (FAPDs) compared with healthy peers.

KEY RESULTS

Of 1496 children, 281 (mean age 12.9 ± 2.2 years, 49.8% females) self-reported criteria for DGBIs and 125 reported (44.5%) FAPDs. Children with DGBIs had higher trait anxiety, emotional sensitivity, somatization including GI, non-GI, pain-related, and non-pain-related subscales (p < 0.001 each) and lower coping efficacy (p = 0.02) compared to healthy peers. Females had higher trait anxiety and somatization (p = 0.04 and p = 0.005, respectively). State and trait anxiety and coping efficacy differed based on location in children with DGBIs (p = 0.02, p = 0.03, and p < 0.001, respectively). Children with FAPDs had higher trait anxiety (p = 0.02) and somatization (p < 0.001) compared to healthy youth.

CONCLUSIONS & INFERENCES

Children with DGBIs had higher anxiety, emotional sensitivity, and somatization, and lower coping efficacy compared with healthy youth. This highlights the importance of appraising psychological distress characteristics as well as incorporating conflict resolution, assertiveness training, and resilience building during the treatment of DGBIs.

Altered gut microbial profile is associated with differentially expressed fecal microRNAs in patients with functional constipation

While dysbiosis within the intestinal ecosystem has been associated with functional constipation (FC), the mechanisms underlying the interactions between FC and the microbiome remain poorly elucidated. Recent investigations suggested that host microRNAs (miRNAs) can modulate bacterial growth and influence the composition of the gut microbiome. To explore the connection between gut microbiota and fecal miRNAs in FC patients, we initially employed 16S rRNA sequencing to assess the gut microbial landscape in 30 FC patients and 30 healthy controls (HCs). The α-diversity within the FC group exhibited some alterations, and the β-diversity significantly differed, signifying distinctive variations in gut microbiota composition between FC patients and HCs. Subsequently, we identified 44 differentially expressed (DE) miRNAs in feces from FC patients and HCs. Through correlation analysis between DE miRNAs and FC-associated microbiota, we detected an interaction involving nine DE miRNAs (miR-205-5p, miR-493-5p, miR-215-5p, miR-184, miR-378c, miR-335-5p, miR-514a-3p, miR-141-3p, and miR-34c-5p) with seven bacterial genera (Oscillibacter, Escherichia.Shigella, UCG.002, Lachnospiraceae_NK4A136_group, Lachnospiraceae_UCG.010, Eubacterium_ruminantium_group and Megamonas), as evidenced by a co-occurrence network. Further, a comprehensive panel of seven diagnostic biomarkers (Oscillibacter, Escherichia.Shigella, UCG.002, miR-205-5p, miR-493-5p, miR-215-5p, and Lachnospiraceae_NK4A136_group) demonstrated robust discriminatory capacity in predicting FC status when integrated into a random forest model (AUC = 0.832, 95% CI: 65.73-98.88). Microbiomes correlating with DE miRNAs exhibited enrichment in distinct predicted metabolic categories. Moreover, miRNAs correlated with FC-associated bacteria were found to be enriched in signaling pathways linked to colonic contractility, including Axon guidance, PI3K-Akt signaling pathway, MAPK signaling pathway, and Hippo signaling pathway. Our study offers a comprehensive insight into the global relationship between microbiota and fecal miRNAs in the context of FC, presenting potential targets for further experimental validation and therapeutic interventions.

Age Differences in Upper Gastrointestinal Symptoms and Vagal Modulation in Women With Irritable Bowel Syndrome

BACKGROUND/AIMS

Patients with irritable bowel syndrome (IBS) often report upper gastrointestinal (GI) (e.g., nausea and heartburn), somatic, and emotional symptoms. This study seeks to examine the relationships among younger and older women with IBS and indicators of autonomic nervous system (ANS) function and daily nausea and heartburn symptoms.

METHODS

Women were recruited through clinics and the community. Nocturnal heart rate variability (HRV) was obtained using ambulatory electrocardiogram Holter monitors. Individual symptom severity and frequency were collected using 28-day diaries. All variables were stratified by younger (<46 years) and older (≥46 years) age groups.

RESULTS

Eighty-nine women with IBS were included in this descriptive correlation study (n = 57 younger; n = 32 older). Older women had reduced indices of vagal activity when compared to younger women. In older women, there was an inverse correlation between nausea and vagal measures (Ln RMSSD, r = -.41, p = .026; Ln pNN50, r = -.39, p = .034). Heartburn in older women was associated with sleepiness (r = .59, p < .001) and anger (r = .48, p = .006). Nausea was significantly correlated with anger in the younger group (r = .41, p = .001). There were no significant relationships between HRV indicators and nausea and heartburn in younger women.

CONCLUSIONS

Age-related differences in ANS function that are associated with nausea may portend unique opportunities to better understand the vagal dysregulation in women with IBS.

Irritable bowel syndrome - controversies in diagnosis and management

INTRODUCTION

The irritable bowel syndrome (IBS) is the best-recognized disorder of gut brain interactions (DGBI). However, it is controversial if the Rome IV criteria iteration for IBS diagnosis is fit for purpose.

AREAS COVERED

This review critically evaluates Rome IV criteria for diagnosis of IBS and addresses clinical considerations in IBS treatment and management, including dietary factors, biomarkers, disease mimics, symptom severity, and subtypes. The role of diet in IBS is critically reviewed along with the influence of the microbiota, including small intestinal bacterial overgrowth.

EXPERT OPINION

Emerging data suggest the Rome IV criteria are more suitable for identifying severe IBS and least useful for sub-diagnostic patients who are still likely to benefit from IBS treatment. Despite convincing evidence that IBS symptoms are diet-driven and often postprandial, a relationship to eating is not a Rome IV diagnostic criterion. Few IBS biomarkers have been identified, suggesting the syndrome is too heterogeneous to be measured by a single marker, and combined biomarker, clinical, dietary, and microbial profiling may be needed for objective characterization. With many organic diseases mimicking and overlapping with IBS, it's important clinicians are knowledgable about this to mitigate the risk of missing comorbid organic intestinal disease and to optimally treat IBS symptoms.

Differential Diagnosis of Chronic Diarrhea: An Algorithm to Distinguish Irritable Bowel Syndrome With Diarrhea From Other Organic Gastrointestinal Diseases, With Special Focus on Exocrine Pancreatic Insufficiency

Chronic diarrhea, defined as diarrhea persisting for more than 4 weeks, affects up to 5% of the population regardless of patient age, sex, race, or socioeconomic status. The impact on patient health and quality of life is substantial, and diagnosis and management of these patients have significant economic consequences for health care services. The differential diagnosis of chronic diarrhea is broad, with etiologies including infections, endocrinopathies, maldigestive/malabsorptive conditions, and disorders of gut-brain interaction. The considerable overlap of symptoms across this spectrum makes accurate diagnosis problematic and may lead to delays in diagnosis or misdiagnosis. In this narrative review, we consider the differential diagnosis of chronic diarrhea, focusing on irritable bowel syndrome with diarrhea and exocrine pancreatic insufficiency, two conditions that may present similarly but have very different underlying causes and require significantly different management strategies. We outline a 4-step diagnostic strategy and propose a straightforward algorithm to assist in efficiently differentiating irritable bowel syndrome from exocrine pancreatic insufficiency and other causes of chronic diarrhea. We anticipate that these aids will improve diagnostic accuracy, which ultimately should lead to improvements in patients' health-related quality of life and reduce the societal burden on health care services.

Somatization is associated with altered serum levels of vitamin D, serotonin, and brain-derived neurotrophic factor in patients with predominant diarrhea irritable bowel syndrome

BACKGROUND

Patients with irritable bowel syndrome (IBS) often show psychological disorders, including somatization, usually driven by an altered gut-brain axis. These changes are also accompanied by modifications in the circulating levels of vitamin D (VD) and neurotransmitters such as serotonin (5-HT) and brain-derived neurotrophic factor (BDNF). The present study aimed to evaluate the relationship between gastrointestinal (GI) symptoms and circulating levels of VD, 5-HT, and BDNF in IBS patients with diarrhea (IBS-D) categorized according to somatization.

METHODS

Fifty-three IBS-D patients were recruited and profiled for GI symptoms by validated questionnaires. The fasting serum concentrations of VD, 5-HT, and BDNF were assessed. The health of the intestinal barrier, minimal inflammation, and dysbiosis was also evaluated.

KEY RESULTS

Thirty patients showed high somatization scores, IBS-D(S+), and 23 low somatization scores, IBS-D(S-). IBS-D(S+) patients reported higher "Abdominal pain" and the "Abdominal pain duration in days" scores, lower serum VD levels and increased 5-HT and BDNF concentrations than IBS-D(S-). Besides, in IBS-D(S+) patients, the GI symptoms correlated with 5HT, BDNF, and VD concentrations. These parameters were associated with impaired small intestinal permeability and increased inflammation markers.

CONCLUSIONS AND INFERENCES

These data support the multifactorial IBS pathogenesis in which organic and psychological factors interact. An active role by VD, 5-HT, and BDNF in affecting the clinical and biochemical profiles in IBS-D(S+) patients may be conceivable. Therefore, the routine VD estimation and the assay of circulating levels of 5-HT and BDNF could be considered a new approach for managing these patients.

Current and Future Therapeutic Options for Irritable Bowel Syndrome with Diarrhea and Functional Diarrhea

Irritable bowel syndrome with diarrhea and functional diarrhea are disorders of gut-brain interaction presenting with chronic diarrhea; they have significant impact on quality of life. The two conditions may exist as a continuum and their treatment may overlap. Response to first-line therapy with antispasmodics and anti-diarrheal agents is variable, leaving several patients with suboptimal symptom control and need for alternative therapeutic options. Our aim was to discuss current pharmacologic options and explore alternative therapeutic approaches and future perspectives for symptom management in irritable bowel syndrome with diarrhea and functional diarrhea. We conducted a search of PubMed, Cochrane, clinicaltrial.gov, major meeting abstracts for publications on current, alternative, and emerging drugs for irritable bowel syndrome with diarrhea and functional diarrhea. Currently approved therapeutic options for patients with first-line refractory irritable bowel syndrome with diarrhea and functional diarrhea include serotonin-3 receptor antagonists, eluxadoline and rifaximin. Despite their proven efficacy, cost and availability worldwide impact their utilization. One-third of patients with disorders of gut-brain interaction with diarrhea have bile acid diarrhea and may benefit from drugs targeting bile acid synthesis and excretion. Further understanding of underlying pathophysiology of irritable bowel syndrome with diarrhea and functional diarrhea related to bile acid metabolism, gastrointestinal transit, and microbiome has led to evaluation of novel therapeutic approaches, including fecal microbiota transplantation and enterobacterial "crapsules". These opportunities to treat disorders of gut-brain interaction with diarrhea should be followed with formal studies utilizing large samples of well-characterized patients at baseline and validated response outcomes as endpoints for regulatory approval.

Extraintestinal manifestations in irritable bowel syndrome: A systematic review

Background

Irritable bowel syndrome (IBS) is characterized by abdominal pain and altered bowel habits. Further, IBS patients experience a high degree of extraintestinal symptoms.

Objectives

The aim of this review was to describe the relation between IBS and extraintestinal manifestations and mechanisms and treatments of these extraintestinal manifestations.

Design

The study was performed as a systematic review.

Data Sources and Methods

Search terms including extraintestinal manifestations or somatization and IBS were used to scrutinize for publications in Pubmed. In total, 630 publications were identified and 80 were finally included in this review.

Results

About 50% of all IBS patients have extraintestinal manifestations in addition to gastrointestinal symptoms. Somatic pain, fatigue, and sleeping disturbances are most common, and most often described in women. Both extraintestinal manifestations and psychological distress are associated with exaggerated gastrointestinal symptoms, impaired quality of life, and difficulties to treat IBS symptoms. The extraintestinal manifestations render an excess of healthcare costs. Varying etiology and pathophysiology to IBS are discussed, and many patients express a general hypersensitivity. Extraintestinal symptoms are seldom documented at clinical healthcare or included in the assessment of treatment outcomes. A good patient-physician relationship and strengthening of coping mechanisms have rendered less gastrointestinal symptoms, psychological distress, and somatization. Altered lifestyle habits may improve both gastrointestinal and extraintestinal symptoms. Pharmacological treatment, including antidepressant drugs, should be considered when lifestyle advice fails. Teamwork between different specialists and healthcare providers may be of importance in the wide range of symptoms and extraintestinal manifestations.

Conclusion

Extraintestinal manifestations are common in IBS patients and is associated with worse suffering and difficulties to treat symptoms. Evaluation and treatment of IBS patients should consider also extraintestinal manifestations and their treatment outcome. Establishment of good relationship, strengthening of coping mechanisms, and education in healthier lifestyle habits are crucial in the management of these patients.

Functional gastrointestinal and somatoform symptoms five months after SARS-CoV-2 infection: A controlled cohort study

BACKGROUND

Gastrointestinal infections represent a risk factor for functional gastrointestinal and somatoform extraintestinal disorders. We investigated the prevalence and relative risk (RR) of gastrointestinal and somatoform symptoms 5 months after SARS-CoV-2 infection compared with a control cohort.

METHODS

One hundred and sixty-four SARS-CoV-2 infected patients and 183 controls responded to an online questionnaire about symptoms and signs during the acute phase of the infection and after 4.8 ± 0.3 months. Presence and severity of gastrointestinal symptoms, somatization, anxiety, and depression were recorded with standardized questionnaires. Stool form and presence of irritable bowel syndrome (IBS) were also recorded. Any association between exposure to infection and symptoms was evaluated by calculating crude and adjusted RR values and score differences with 95% confidence intervals (CI).

KEY RESULTS

Fever, dyspnea, loss of smell/taste/weight, diarrhea, myalgia, arthralgia, and asthenia were reported by more than 40% of patients during the acute phase. Compared with controls, adjusted RRs for loose stools, chronic fatigue, and somatization were increased after infection: 1.88 (95% CI 0.99-3.54), 2.24 (95% CI 1.48-3.37), and 3.62 (95% CI 1.01-6.23), respectively. Gastrointestinal sequelae were greater in patients with diarrhea during the acute phase.

CONCLUSIONS & INFERENCES

Mild gastroenterological symptoms persist 5 months after SARS-CoV-2 infection, in particular in patients reporting diarrhea in the acute phase. Infected patients are at increased risk of chronic fatigue and somatoform disorders, thus supporting the hypothesis that both functional gastrointestinal and somatoform disorders may have a common biological origin.