Mechanisms underlying storage lower urinary tract symptoms in men

Background. Storage lower urinary tract symptoms (LUTS) in men can arise from obstruction, bladder dysfunction, chronic pelvic pain, stone disease, or impaired outlet coordination. Similar symptoms do not establish a common cause. This structured narrative review compares these mechanisms and examines the limited evidence linking urinary crystals or stone-risk chemistry to storage symptoms. Pelvic floor and sphincter electromyography (EMG) and the bulbocavernosus reflex (BCR) are considered separately as selective functional or neurological tests. Ten targeted PubMed searches were performed on August 8, 2026, supplemented by searches of clinical guidelines and known relevant publications. The evidence was compared across populations, study designs, outcomes, and relevance to male storage LUTS. Independent human screening, full-text eligibility adjudication, and formal risk-of-bias assessment were not documented in the search archive; this is not a systematic review. Studies in men show that obstruction and storage dysfunction can coexist and that symptoms may persist after deobstruction. Associations between prostatic calcification and symptom severity are inconsistent. Evidence concerning urine pH, calcium excretion, alkalinization, and metabolomics is largely observational, mixed-sex, or female-only. It does not validate a distinct crystallogenic syndrome or support routine alkalinization for male storage LUTS. Surface pelvic floor, anal sphincter, and external urethral sphincter EMG are not interchangeable. The BCR assesses a sacral somatic pathway, not urinary crystallization or bladder storage function. Clinical evaluation should address specific diagnostic questions. Future male cohorts need prespecified comparison groups, repeated urine measurements, and a single primary outcome.