Altered colonic motility is associated with low anterior resection syndrome

Abstract

Aim Patients frequently suffer from low anterior resection syndrome (LARS) after distal colorectal resection. The pathophysiology of LARS has not been clearly elucidated. We hypothesized that rectosigmoid resection could impair motility patterns in the distal colon, such as the rectosigmoid brake, which contribute to control of stool form and frequency. Method High‐resolution colonic manometry was performed in patients who had previously undergone distal colorectal resection (mean 6.8 years after resection) and non‐operative controls before and after a standardized meal. Symptoms were assessed using the LARS score. Propagating contractions were compared between patients with and without LARS, and controls. Results Data were analysed from 23 patients (11 no‐LARS; 12 LARS) and nine controls. All groups demonstrated a significant meal response. LARS patients had fewer post‐prandial antegrade propagating contractions than controls (P = 0.028), and fewer retrograde propagating contractions both pre‐ (P = 0.005) and post‐prandially (P = 0.004). Post‐prandially, the LARS group had a significantly lower percentage of propagating contractions that met the criteria for the cyclic motor pattern compared to the control group (26% vs. 58%; P = 0.009). There were significant differences in antegrade and retrograde amplitude (P = 0.049; P = 0.018) and distance of propagation (P = 0.003; P = 0.002) post‐prandially between LARS patients and controls. Conclusion Rectosigmoid resection alters the meal response following anterior resection, including impairment of the rectosigmoid brake cyclic motor pattern. These findings help to quantify the impaired functional motility after rectosigmoid resection and offer new insights into the mechanisms of LARS.

Variable Gut Function Recovery After Right vs. Left Colectomy May Be Due to Rectosigmoid Hyperactivity

“…In right colectomy patients, EColG could be expected to demonstrate varying durations of hyperactivity occurring in the rectosigmoid region. For left sided resections, depending on how much of the rectosigmoid junction has been resected, reduced activity would be anticipated, as recently revealed in patients suffering chronic Low Anterior Resection Syndrome ( Keane et al, 2020 ).…”

Low anterior resection syndrome – ‘braking’ our focus with the pelvis

“…The predominant retrograde direction of these complexes in the sigmoid colon and rectum suggests they resist anally directed flow and assist in the maintenance of continence and control of defaecation [5]. Ingestion of a meal rapidly increases the occurrence and amplitude of this cyclic activity, suggesting that extrinsic nerves can modulate it – the proposed ‘rectosigmoid brake’ [4].…”

“…However, the important thought‐provoking study by Keane et al . in this month's issue of Colorectal Disease demonstrates that altered colonic motility has a significant role to play [4].…”

“…The current study uses high‐resolution colonic manometry in patients who had previously undergone distal colorectal resection and nonoperative controls who had a standardized meal, and the resulting values were correlated with symptoms quantified using the LARS score [4]. High‐resolution manometry provides intraluminal pressure readings at closely spaced intervals, achieving more detailed spatiotemporal data than previous lower resolution approaches.…”

Altered colonic motility is associated with low anterior resection syndrome, by Keane et al

“…In February's edition of Colorectal Disease, Keane et al present their paper on colonic motility and its association with low anterior resections syndrome (LARS) [1]. I chose this paper as we know the high prevalence (60–90%) and significant impact that LARS can have on our patients and that there is a need to better understand its likely multi‐factorial aetiology.…”