Lifestyle Modifications for Faecal Incontinence in Functional Gastrointestinal Disorders: A Systematic Review of Evidence and Outcomes

Faecal incontinence (FI) is a distressing, often under-reported problem among functional gastrointestinal disorders (FGIDs), but the role of lifestyle modification has not been fully synthesized. This systematic review examined evidence from 2000 to 2025 on dietary, behavioural, pelvic floor, and physical activity strategies for FI associated with FGIDs, including irritable bowel syndrome, functional diarrhoea, and functional constipation. PubMed, Scopus, Web of Science, and Google Scholar were searched using PRISMA principles. Eligible studies included adults or children with FI or related functional bowel patterns and reported outcomes such as FI frequency, symptom severity, stool consistency, bowel habits, and quality of life. Evidence was organized across epidemiology, mechanisms, diagnostic assessment, dietary management, conservative therapy, special populations, and psychosocial impact. Overall, FI in patients with FGIDs is best understood as a multifactorial outcome involving stool form, urgency, transit, rectal sensation, pelvic floor coordination, comorbid disease, medications, mobility, cognition, and psychosocial distress. Dietary modification, especially soluble fibre titration, food and bowel diaries, and trigger-food management, consistently supported stool form control and symptom predictability. Pelvic floor muscle training and biofeedback relieved symptom severity and improved patient-reported outcomes, particularly when delivered via trained clinicians and combined with stool form management. Physical activity and bowel retraining showed supportive but less developed evidence. Heterogeneity in definitions, outcomes, intervention protocols, and follow-up limited quantitative comparisons. Lifestyle modification should be considered a safe, scalable first-line or adjunctive strategy for FI in patients with FGIDs. Future research should use standardized FI scales, stool form measures, bowel diaries, quality-of-life instruments, and longer follow-up to guide personalized care.