Background/Objectives: Constipation is a common gastrointestinal problem in older adults and is associated with reduced quality of life, functional decline, frailty, and an increased risk of delirium and cognitive impairment. Its pathogenesis is multifactorial, involving age-related changes in gastrointestinal motility, neural regulation, comorbidities, and polypharmacy. However, this condition has traditionally been regarded as a localized gastrointestinal disorder, which may not fully reflect its systemic clinical significance in older populations. While prior narrative reviews have described multifactorial contributors to constipation, none have formally applied a geriatric syndrome framework to integrate these dimensions. This review proposes a three-criterion operational definition—multifactorial pathogenesis, association with functional decline and frailty, and contribution to adverse systemic outcomes—to characterize constipation in older adults as a “systemic geriatric syndrome,” and evaluates available evidence against each criterion. Methods: A narrative literature search was conducted using PubMed to identify relevant studies published between 1 January 2023, and 31 December 2025. MeSH terms included “Constipation” Major Topic and “Aged” MeSH Terms. Eligible articles included English-language original studies, systematic reviews, and clinical or epidemiological studies involving individuals aged ≥65 years. Results: Diagnosis in older adults is often complicated by secondary causes, including medications and neurological disorders, as well as atypical symptom presentations in individuals with cognitive impairment. Key pathophysiological mechanisms include reductions in interstitial cells of Cajal, impaired smooth muscle contractility, dysfunction of the enteric and autonomic nervous systems, and gut microbiota dysbiosis, which may promote chronic low-grade inflammation. Major contributing factors include physical inactivity, sarcopenia, dehydration, inappropriate defecation posture, and polypharmacy, particularly opioids and anticholinergic agents. Importantly, these factors interact through the brain–gut–microbiota axis, contributing not only to gastrointestinal dysfunction but also to systemic outcomes such as frailty, cognitive decline, and increased healthcare burden, thereby supporting a multidimensional disease framework. Conclusions: The available evidence collectively supports the plausibility of framing constipation in older adults as a systemic geriatric syndrome, though formal validation of this classification requires further longitudinal and mechanistic research. Comprehensive and individualized management strategies, extending beyond simple laxative use, are essential to reduce complications and preserve functional health in aging populations. Further studies are required to validate this framework.
Mimura et al. (Thu,) studied this question.