ASCRS Ch62 - Low Anterior Resection Syndrome

Chapter 62 of the ASCRS Textbook of Colon and Rectal Surgery, 4th edition. PDF pages 1033-1040, book pages 1047-1054 (offset +14, unchanged from Ch61 — confirmed via the "© Springer Nature Switzerland AG 2022 1047" copyright line on the chapter's first PDF page). Ch62 ends on book page 1054, an even page, so per this wiki's offset-tracking rule (a new chapter starts on the next odd/recto page in print, forcing a blank page that's dropped from the PDF, which only shows up as an offset jump when the previous chapter ends on an odd page) the offset does not jump at the Ch62/Ch63 boundary — confirmed: Ch63 ("Sexual Function After Colorectal Surgery") begins at PDF page 1041/book page 1055, offset +14 unchanged.

Structure and content

The chapter is dedicated entirely to low anterior resection syndrome (LARS), covering:

• Definition and incidence: chronicity data (58%/46%/41% at 3/12/54 months with major symptoms); the finding that 85% of patients retaining most/all of the rectum remain continent yet 42% still meet LARS criteria; LARS-like symptoms in patients with a preserved rectum after pelvic chemoradiotherapy (up to 50%).
• Delphi consensus definition: 325 experts including 156 patients with LARS; describes it in this chapter's own text as "eight symptoms and five consequences" — conflicting with the previously-ingested ASCRS Ch29 - Proctectomy for Rectal Cancer's "eight symptoms and eight consequences" from the same underlying consensus. This chapter's own Fig 62.1 table (badly garbled by pdfplumber's multi-column-to-text flattening) appears on inspection to actually enumerate more than five consequence-like phrases, suggesting "five" is a transcription artifact rather than a genuine second consensus figure — flagged rather than silently resolved, on both this page and Low Anterior Resection Syndrome (LARS).
• Cause: explicitly framed as poorly understood, with none of the proposed mechanisms properly studied or validated; adds autonomic denervation, increased colonic motility, and radiotherapy-related mucosal damage to the mechanism list; a dedicated risk-factor list (age, female sex, tumor location, mesorectal dissection extent, neoadjuvant radiation, loop ileostomy).
• Prediction/counseling: the POLARS (Preoperative LARS) nomogram (Battersby et al.) and guidance on discussing end colostomy as an alternative during informed consent.
• Prevention: reservoir options (J-pouch, coloplasty, side-to-end), with a caveat that the J-pouch's short-term functional advantage may not persist to 18 months in at least one study, and that no intervention is definitively proven to prevent LARS.
• Diagnosis / exclusion of mimics: pancreatic malabsorption, SIBO, 5-FU-induced lactose intolerance, radiation enteritis, anastomotic strictures, ischemic conduits, local recurrence; cholestyramine trial; flexible sigmoidoscopy for symptomatic patients within 5 years of surgery.
• Treatment: framed as chronic-disease management (additive, not replacement; "Listen, Educate, Treat"), citing a postoperative screening/treatment protocol study (mean LARS score 31→18, major LARS rate 51.9%→26.3%) and an algorithmic-care RCT. Full treatment ladder: medical therapy (fiber, loperamide → opiates, amitriptyline, 5-HT3 antagonists, probiotics negative trial, topical skin care), biofeedback/pelvic floor retraining (systematic review of 5 studies/321 patients, plus a newer RCT localizing benefit to the FI component), retrograde colonic irrigation (RCI — full technique, three cited studies including a 37-patient RCI-vs-PTNS RCT), sacral neuromodulation (systematic review: 94 screened, 75/94=79.8% implanted, 67.0% median LARS-score improvement), percutaneous tibial nerve stimulation (not available in the USA; cites the CONFIDeNT sham-RCT), antegrade continence enemas (2016 meta-analysis of 17 studies, 83.6% pooled success; a PEC-tube cohort), and fecal diversion as a last resort.

Wiki integration

All content merged into Low Anterior Resection Syndrome (LARS) (near-total expansion — new Prediction/Diagnosis sections, entirely new RCI subsection, expanded SNM/PTNS/ACE/medical-therapy detail, explicit reconciliation of this chapter's SNM figures against the pre-existing Ch29-sourced SNS figures rather than merging them). No new procedure pages were split out — sphincteroplasty-adjacent and device-based treatments already have their primary technique detail on Fecal Incontinence and are cross-referenced from the LARS page rather than duplicated.

Offset tracking

• Chapter starts: PDF p.1033, book p.1047 (offset +14, confirmed via copyright line; unchanged from Ch61).
• Chapter ends: book p.1054 (even page) → no jump expected or found at the Ch62/Ch63 boundary.
• Ch63 confirmed starting at PDF p.1041/book p.1055, offset +14 unchanged.