Systematic review synthesizes manometry evidence on rectosigmoid brake's role in surgical colorectal conditions, suggesting its clinical importance.
Background The rectosigmoid brake (RSB) regulates rectal filling via retrograde cyclic motor patterns in the distal colon. Disruption has been linked to postoperative ileus (POI), low anterior resection syndrome (LARS), fecal incontinence (FI), and acute colonic pseudo‐obstruction (ACPO). We synthesized manometric evidence to clarify the RSB's clinical relevance. Methods A systematic search of Ovid MEDLINE and Embase (March 2025) for studies assessing distal colonic motility in adults with surgical or functional colorectal conditions. Thirty‐four studies met the inclusion criteria, including nine using high‐resolution manometry. Data were qualitatively synthesized by condition. Key Results Altered RSB activity was a consistent finding. In POI (7 studies; 2 HRM), the HRM studies showed immediate postoperative hyperactive distal cyclic activity (~2–4 cycles/min) correlating with delayed return of bowel function, contradicting older low‐resolution reports of quiescence. In LARS (4 studies; 3 HRM), post‐prandial cyclic patterns and propagating sequences were blunted after rectosigmoid resection. In FI (5 studies; 2 HRM), the brake was suppressed; sacral nerve stimulation increased distal retrograde contractions with parallel symptom gains. In ACPO (1 HRM case study), recordings showed disordered, non‐propagating hyperactive activity consistent with distal functional obstruction rather than hypoactivity. Conclusions Across POI, LARS, FI, and ACPO, the RSB appears to be a unifying physiological mechanism and a promising physiological biomarker with diagnostic and therapeutic potential. Priorities include standardizing manometric definitions, establishing normative reference metrics, and advancing non‐invasive assessment (e.g., body‐surface colonic mapping) to enable RSB‐guided care and translation to practice.
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Penfold et al. (2026) studied this question.
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