Characteristics of patients with overlap functional gastrointestinal disorders

Unsupervised machine learning highlights the challenges of subtyping disorders of gut-brain interaction

BACKGROUND

Unsupervised machine learning describes a collection of powerful techniques that seek to identify hidden patterns in unlabeled data. These techniques can be broadly categorized into dimension reduction, which transforms and combines the original set of measurements to simplify data, and cluster analysis, which seeks to group subjects based on some measure of similarity. Unsupervised machine learning can be used to explore alternative subtyping of disorders of gut-brain interaction (DGBI) compared to the existing gastrointestinal symptom-based definitions of Rome IV.

PURPOSE

This present review aims to familiarize the reader with fundamental concepts of unsupervised machine learning using accessible definitions and provide a critical summary of their application to the evaluation of DGBI subtyping. By considering the overlap between Rome IV clinical definitions and identified clusters, along with clinical and physiological insights, this paper speculates on the possible implications for DGBI. Also considered are algorithmic developments in the unsupervised machine learning community that may help leverage increasingly available omics data to explore biologically informed definitions. Unsupervised machine learning challenges the modern subtyping of DGBI and, with the necessary clinical validation, has the potential to enhance future iterations of the Rome criteria to identify more homogeneous, diagnosable, and treatable patient populations.

Epidemiology of Disorders of the Gut-Brain Interaction: An Appraisal of the Rome IV Criteria and Beyond

Disorders of the gut-brain interaction (DGBIs) are presently classified into mutually exclusive anatomical area-related symptom-based categories according to the Rome IV criteria. The pathophysiology of visceral nociception, which contributes to the wide range of symptoms of DGBIs, involves complex psychobiological processes arising from the bidirectional interactions of multiple systems at the gut and brain levels, which affect symptom expression and illness behaviors. The attitude toward an illness and expression of pain and bowel habit vary across cultures with variable interpretation based on sociocultural beliefs, which may not tally with the medical definitions. Thus, psychological factors impact DGBI definitions, their severity and health care utilization. Due to the poor localization and multisegment referral of visceral pain, the anatomical site of pain may not correspond to the affected segment, and there may be a variable degree of overlap among symptoms. The somewhat restrictively defined Rome IV criteria assume one-to-one correlation of symptoms with underlying pathophysiology and ignore overlapping DGBIs, nonstandardized symptom categories, and change or shift in category over time. The microorganic nature of DGBIs resulting from systemic, metabolic or motility disorders, gut dysbiosis and inflammation are not addressed in the Rome IV criteria. Although there is a multidimensional clinical profile that does address these factors, it is not followed rigorously in practice. Threshold changes for diagnostic criteria or addition/deletion of symptoms leads to wide variation among different DGBI criteria resulting in uncertain comparability of results. Although the Rome IV criteria are excellent for research studies and therapeutic trials in homogenous populations, further improvement is needed for their wider applicability in clinical practice.

Defecation symptoms in primary health care patients with irritable bowel syndrome

BACKGROUND

The objectives of the present study were to (a) measure the prevalence of defecation symptoms in IBS, (b) investigate the relationship between stool consistency and defecation symptoms in IBS, and (c) investigate the association of defecation symptoms with health-related quality of life (HRQL) and self-reported stress in patients with IBS cared for in a primary health care setting.

METHODS

Ten primary health care centres joined the study. 282 patients with IBS as well as 372 non-IBS controls filled in gastrointestinal symptom diaries prospectively for two weeks as well as the Perceived Stress Scale-14 (PSS14) and the EuroQol barometer to measure perceived stress and HRQL, respectively.

RESULTS

Incomplete evacuation was present in 51% vs. 21% of the stools among the IBS patients and the non-IBS controls, respectively. The need to strain during defecation was existing in 41% vs. 33% of the stools for the IBS patients and the non-IBS controls, respectively. Urgency was experienced in 37% of the stools in the IBS patients compared with 18% of the stools in the non-IBS controls. Patients with IBS experienced in a significant higher degree of overlapping symptoms per stool (p < 0.001 to p = 0.007). The occurrence of all defecation symptoms in the same patient was related to decreased HRQL, and increased stress (p = 0.001 to p < 0.001).

CONCLUSIONS

An overlap between IBS and symptoms from the anorectal region related to defecation was found in a primary health care population. Defecation symptoms are very common in primary care IBS-patients, it co-occurs with increased self-perceived stress, and decreased HRQL.

Psychological status of patients with functional anorectal pain and treatment efficacy of paroxetine in alleviating the symptoms: a retrospective study

The aim of this study was to investigate the clinical characteristics, psychological status, sleep quality, and quality of life of patients with functional anorectal pain (FAP). The study also assessed the treatment efficacy of paroxetine in alleviating FAP symptoms. A retrospective comparative study of forty-three patients with FAP who were first treated with an anal plug compound glycolate suppository versus paroxetine combined with anal plug compound glycolate suppository between November 2021 and August 2022. Pain, quality of life, depression, anxiety and sleep quality were assessed before and after treatment by the Chinese version of the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2), Health-related quality of life scale (The 12-Item Short-Form Health Survey, SF-12), 17-item Hamilton Depression Rating Scale (HDRS), 14-item Hamilton Anxiety Scale (HAMA), and Pittsburgh Sleep Quality Index (PSQI). A total of 46.5% of patients with FAP were found to have anxiety symptoms (HAMA ≥ 7), 37.2% of patients with FAP were found to have depressive symptoms (HDRS ≥ 8). A total of 32.6% of patients with FAP had sleep disorders (PSQI > 10). Within 1 week after drug withdrawal, the short-term efficacy rate of oral paroxetine was 95.5%. After treatment, the symptom pain score (VAS) and sleep score were lower than those before treatment (P < 0.01). In the areas of vitality (VT), Social Functioning (SF), and Mental Health (MH), the difference between the pre-treatment and 8 weeks posttreatment scores of the study group and the control group was statistically significant (P < 0.05). FAP patients have obvious symptoms of anxiety and depression, and the incidence of sleep disturbance is prevalent. Paroxetine, a typical serotonin reuptake inhibitor (SSRI), was able to alleviate depression, anxiety, and pain symptoms in FAP, which might have clinical application prospects.

Re-investigation of functional gastrointestinal disorders utilizing a machine learning approach

BACKGROUND

Functional gastrointestinal disorders (FGIDs), as a group of syndromes with no identified structural or pathophysiological biomarkers, are currently classified by Rome criteria based on gastrointestinal symptoms (GI). However, the high overlap among FGIDs in patients makes treatment and identifying underlying mechanisms challenging. Furthermore, disregarding psychological factors in the current classification, despite their approved relationship with GI symptoms, underlines the necessity of more investigation into grouping FGID patients. We aimed to provide more homogenous and well-separated clusters based on both GI and psychological characteristics for patients with FGIDs using an unsupervised machine learning algorithm.

METHODS

Based on a cross-sectional study, 3765 (79%) patients with at least one FGID were included in the current study. In the first step, the clustering utilizing a machine learning algorithm was merely executed based on GI symptoms. In the second step, considering the previous step's results and focusing on the clusters with a diverse combination of GI symptoms, the clustering was re-conducted based on both GI symptoms and psychological factors.

RESULTS

The first phase clustering of all participants based on GI symptoms resulted in the formation of pure and non-pure clusters. Pure clusters exactly illustrated the properties of most pure Rome syndromes. Re-clustering the members of the non-pure clusters based on GI and psychological factors (i.e., the second clustering step) resulted in eight new clusters, indicating the dominance of multiple factors but well-discriminated from other clusters. The results of the second step especially highlight the impact of psychological factors in grouping FGIDs.

CONCLUSIONS

In the current study, the existence of Rome disorders, which were previously defined by expert opinion-based consensus, was approved, and, eight new clusters with multiple dominant symptoms based on GI and psychological factors were also introduced. The more homogeneous clusters of patients could lead to the design of more precise clinical experiments and further targeted patient care.

Overlap of disorders of gut-brain interaction: a systematic review and meta-analysis

BACKGROUND

Rome criteria differentiate distinct types of disorders of gut-brain interaction (DGBI); also known as functional gastrointestinal disorders. Overlap of symptom categories frequently occurs. This systematic review and meta-analysis aimed to define the prevalence of DGBI overlap and compare overlap in population-based, primary care or tertiary care health settings. Furthermore, we aimed to compare symptom severity of psychological comorbidities in DGBI with and without overlap.

METHODS

For this systematic review and meta-analysis we searched MEDLINE (PubMed) and Embase electronic databases from inception until March 1, 2022, for original articles and conference abstracts of observational cross-sectional, case-controlled, or cohort design studies that reported the prevalence of DGBI overlap in adult participants (aged ≥18 years). We included only those studies where the diagnosis of DGBI was based on clinical assessment, questionnaire data, or specific symptom-based criteria. Studies were excluded if reporting on mixed populations of DGBI and organic diseases. Aggregate patient data were extracted from eligible published studies. The prevalence of DGBI overlap in all studies was pooled using the DerSimonian and Laird random effects model, and further analysis stratified by subgroups (care setting, diagnostic criteria, geographic region, and gross domestic product per capita). We also assessed the relationship between DGBI overlap with anxiety, depression, and quality of life symptom scores. This study was registered with PROSPERO (CRD42022311101).

FINDINGS

46 of 1268 screened studies, reporting on 75 682 adult DGBI participants, were eligible for inclusion in this systematic review and meta-analysis. Overall, 24 424 (pooled prevalence 36·5% [95% CI 30·7 to 42·6]) participants had a DGBI overlap, with considerable between-study heterogeneity (I2=99·51, p=0·0001). In the tertiary health-care setting, overlap among participants with DGBI was more prevalent (8373 of 22 617, pooled prevalence 47·3% [95% CI 33·2 to 61·7]) compared with population-based cohorts (11 332 of 39 749, pooled prevalence 26·5% [95% CI 20·5 to 33·4]; odds ratio 2·50 [95% CI 1·28 to 4·87]; p=0·0084). Quality of life physical component scores were significantly lower in participants with DGBI overlap compared with participants without overlap (standardised mean difference -0·47 [95% CI -0·80 to -0·14]; p=0·025). Participants with DGBI overlap had both increased symptom scores for anxiety (0·39 [95% CI 0·24 to 0·54]; p=0·0001) and depression (0·41 [0·30 to 0·51]; p=0·0001).

INTERPRETATION

Overlap of DGBI subtypes is frequent, and is more prevalent in tertiary care settings and associated with more severe symptom manifestations or psychological comorbidities. Despite the large sample size, the comparative analyses revealed substantial heterogeneity, and the results should be interpreted with caution.

FUNDING

National Health and Medical Research Council and Centre for Research Excellence.

Experiencing multiple concurrent functional gastrointestinal disorders is associated with greater symptom severity and worse quality of life in chronic constipation and defecation disorders

BACKGROUND

Recent community-based studies have demonstrated that experiencing multiple concurrent functional gastrointestinal disorders (FGIDs) is associated with increased somatization, worse quality of life (QoL), and greater health care utilization. However, the presence of multiple overlapping FGIDs is unstudied specifically in chronic constipation and functional defecation disorders (FDD). We investigated the prevalence and impact of additional nonconstipation FGIDs on constipation severity, anorectal physiology, anxiety and depression, and QoL, in patients with chronic constipation and FDD.

METHODS

One-hundred and forty-six consecutive patients with functional constipation or irritable bowel syndrome (IBS-C/IBS-M) presenting to a tertiary referral Neurogastroenterology Clinic were studied. In addition, 90/146 (62%) qualified for FDD due to abnormal defecatory physiology. Patients underwent comprehensive baseline assessment comprising anorectal physiology, Bristol Stool Chart, Rome questionnaire, Knowles-Eccersley-Scott-Symptom (KESS) constipation score, Hospital Anxiety, and Depression Scale, and modified 36-Item Short Form Health Survey (SF-36) for QoL. Additional FGIDs were diagnosed using Rome III criteria.

KEY RESULTS

Additional nonconstipation FGIDs occurred in 85% of patients, with a mean of 2.1 (SD 1.6) additional FGIDs. Patients with four or more additional FGIDs experienced greater constipation severity compared to those with no additional FGIDs (p = 0.004). Comorbid FGIDs were associated with worse SF-36 scores for physical functioning (p < 0.001), role-physical (p = 0.005), bodily pain (p < 0.001), vitality (p = 0.008), social functioning (p = 0.004), and mental health index (p = 0.031).

CONCLUSIONS AND INFERENCES

Functional gastrointestinal disorders comorbidity is highly prevalent in chronic constipation and defecatory disorders, and this is associated with greater symptom severity and worse QoL. Multimodal treatments targeting comorbid FGIDs may lead to superior outcomes.