Introduction

Avoidant/restrictive eating is common in people with neurogastroenterology disorders including functional dyspepsia (FD). There is debate on whether avoidant/restrictive food intake disorder (ARFID) is an expected response to severe symptoms or simply a common comorbid disorder. To address this, among adults with FD, we aimed to contrast those with and without ARFID on FD symptoms, quality of life, psychosocial factors, nutrient tolerance, and gut transit.

Aims & Methods

Adults with Rome-IV confirmed FD and healthy controls (HC) from an ongoing study participated. ARFID diagnosis was assigned based on a semi-structured DSM-5 diagnostic interview. Surveys: Patient Assessment of GI Disorders Symptom Severity Index (PAGI-SYM), Short Form Nepean Dyspepsia Inventory (SF-NDI), Nine-Item ARFID Screen (NIAS), Fear of Food Questionnaire (FFQ), Visceral Sensitivity Index (VSI), and Hospital Anxiety/Depression Scale (HADS). Nutrient Drink Test (NDT) measured gastric tolerance—liquid nutrient ingestion at 30mL/minute until subject reported unbearable fullness. Wireless Motility Capsule (WMC) measured gut transit. Height/weight was measured for body mass index (BMI).

Results

Sample (80% female, M_age=37.1±14.4y) included 37 FD+ARFID, 14 FD only, and 18 HC. Groups did not significantly differ in sex or age. Adjusted pairwise comparisons showed small (r=.1-.2) non-significant differences between FD and FD+ARFID on FD symptoms by PAGI-SYM and SF-NDI (Table 1). However, FD+ARFID had significantly worse scores compared to FD with medium effects (r=.3-.4) on: FD-related quality of life by SF-NDI, Fear of Food by NIAS-Fear and FFQ, GI-anxiety by VSI, and anxiety by HADS. FD+ARFID vs FD also had small differences (rs=.2) on: feeling more bothered by FD symptoms on SF-NDI, worse depression by HADS, lower BMI, and less NDT consumption. Compared to HC, FD and FD+ARFID had significantly worse survey scores with large effects for FD+ARFID (r=.6-.8) and medium effects for FD vs HC (r=.3-4). For the NDT, FD+ARFID consumed significantly less than HC with large effect (r=.6) but with a trend medium effect for FD consuming less than HC (r=.3). Groups did not significantly differ in WMC transit times.

Conclusion

Our findings suggest ARFID, when present in FD, does not reflect a response to more severe FD symptoms. Thus, ARFID is a legitimate secondary condition in FD. ARFID may reflect more profoundly altered distress around symptoms (e.g., fear of symptoms, anxiety sensitivity) and greater negative impacts (e.g., FD-related quality of life, lower liquid nutrient tolerance).

Introduction

Cognitive Behavioral Therapy (CBT) is an evidence-based treatment for Irritable Bowel Syndrome (IBS), demonstrating long-term improvements in symptoms and quality of life (QOL). However, its implementation is hindered by the complexity of treatment protocols, high time and financial costs, and limited accessibility in Japan.

Aims & Methods

This study aimed to develop a smartphone-based CBT application and evaluate its effectiveness in alleviating IBS symptoms.
Adults aged 18 or older who met the Rome IV criteria for IBS and scored ≥110 on the Japanese version of the IBS Symptom Severity Index (IBSSI-J) were enrolled. Twenty-six participants were randomly assigned to either the intervention group (n = 14) or the waiting-list control group (n = 12). Outcome measures included the IBSSI-J, Japanese versions of the IBS-QOL (IBS-QOL-J), Pain Catastrophizing Scale (PCS-J), and Visceral Sensitivity Index (VSI-J). A two-way ANOVA was conducted with group (intervention vs. control) and time (pre, mid, post, follow-up 1) as independent variables.
The intervention group used the app for 5–10 minutes daily over two months. The app included three components: psychoeducation, cognitive restructuring, and exposure. Psychoeducation consisted of educational materials and follow-up quizzes. Cognitive restructuring used gamified multiple-choice content (135 items), replacing conventional thought records. Exposure involved users creating individual anxiety hierarchies and recording their thoughts before and after exercises. The app visualized anxiety changes and progress via graphs.

Table 1.
Intervention module of the application

Results

Eleven participants in the intervention group and eight in the control group completed the program. Significant group × time interactions were observed for all outcome measures. For the IBSSI-J, the interaction was significant (F(3, 51) = 4.41, p < .001), with the intervention group showing greater improvement at mid-point (F(1, 17) = 5.54, p = .03, η² = .25). For the IBS-QOL-J, a significant interaction was found (F(3, 51) = 8.00, p < .001), with improvement evident at follow-up 1 (F(1, 17) = 6.65, p = .02, η² = .28). For the PCS-J, the interaction was significant (F(3, 51) = 3.83, p = .02), with improvements at post (F(1, 17) = 9.26, p = .01, η² = .35) and follow-up 1 (F(1, 17) = 5.83, p = .03, η² = .26). For the VSI-J, the interaction also reached significance (F(3, 51) = 3.32, p = .05).

Conclusion

The CBT-based app was effective in reducing IBS symptom severity. Its effects persisted after the intervention and extended to improvements in QOL, visceral anxiety, and pain catastrophizing—psychological factors associated with the maintenance and exacerbation of IBS. It is assumed that the cognitive restructuring component of the app facilitated cognitive diversification among participants. By empirically challenging the plausibility of these diversified cognitions through behavioral experiments in the form of exposure tasks, participants were able to further develop more adaptive thoughts. This process is considered to have contributed to the improvement of symptoms and enhancement of QOL. This digital approach may offer a viable solution to current barriers in CBT access.

Clinical Case Summary

A female patient (born 1974) presented with chronic diarrhea (up to 16 times/day, including nocturnal episodes), bloating, periumbilical pain, fatigue, general weakness, and 10 kg weight loss. Since childhood, the patient had been under observation for chronic iron-deficiency anemia of unknown origin without prior gastrointestinal evaluation. Symptoms progressively worsened over two years due to the lack of therapeutic effect at the outpatient stage, leading to hospitalization in July 2022. Histology revealed total duodenal villous atrophy (celiac disease: Marsh 3C, Corazza-Villanacci B2; 30-40 IELs/100 epithelial cells) and lymphocytic microscopic colitis (MC) of the colon (60-70 IELs/100 epithelial cells). Other examinations (abdominal CT, enterography, stool analysis) were normal; labs showed mild iron-deficiency anemia, with protein markers within normal ranges. She was diagnosed with celiac disease combined with lymphocytic MC. A gluten-free diet, iron supplementation, and budesonide (9 mg/day for 3 months) were initiated, leading to clinical improvement. However, diarrhea recurred (up to 10 times/day) one month after stopping budesonide, despite adherence to the gluten-free diet. Duodenal histology improved (Marsh I, IELs ≤20/100 cells), confirming dietary effectiveness for celiac disease. Colonic histology showed ongoing lymphocytic MC activity (25-30 IELs/100 cells). The relapse was attributed to persistent MC. A prolonged regimen of budesonide (9 mg/day for 3 months, tapering to 6 mg/day for 6 months) was prescribed. This clinical case of celiac disease combined with lymphocytic MC demonstrates that significant improvement in small intestine structure can be achieved with a gluten-free diet and prolonged budesonide therapy. However, the recurrent diarrheal syndrome in this case was associated with the persistent course of MC. Literature emphasizes increased MC prevalence in celiac patients, reinforcing the need for timely recognition and combined therapy.

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