ASCRS Ch56 - Functional Disorders After Colorectal Surgery/IBS

Fifty-sixth chapter of the ASCRS Textbook of Colon and Rectal Surgery, 4th edition (Kunitake H, Staller K). Book pages 963–978 (PDF pages 951–966 of raw/ASCRS Textbook 4th Ed.pdf, offset +12 — a jump of +2 from Ch55's +10, confirmed via the "© Springer Nature Switzerland AG 2022 <page>" copyright-line cross-check on this chapter's own first page (963 = 951 + 12). The chapter begins immediately after a "Part V: Pelvic Floor Disorders" section-divider page at PDF page 950/book page 962 — this is the first chapter of a new textbook Part, and the divider page itself appears to be where the extra +2 offset (beyond the usual +1 chapter-to-chapter drift) was absorbed, most likely an unnumbered or differently-numbered front-matter page for the Part opener. Chapter 57 ("Common Tests for the Pelvic Floor") begins immediately at PDF page 967 — its own offset should be reconfirmed independently rather than assumed to continue at +12.

Despite its title, the chapter is a broad functional-disorders survey with two major halves: (1) irritable bowel syndrome (definition, Rome IV subtyping, relationship to colorectal surgery, full treatment ladder), and (2) chronic pelvic pain syndromes relevant to colorectal practice (IBS-associated pelvic pain, functional anorectal pain — levator ani syndrome, unspecified functional anorectal pain, proctalgia fugax — coccygodynia, and pudendal neuralgia). Written from a combined colorectal surgery/GI motility perspective (dual authorship, MGH surgery and gastroenterology).

Key concepts (chapter's own summary box)

• Irritable bowel syndrome (IBS) is defined by the Rome IV criteria and divided into three subtypes (diarrhea-predominant, constipation-predominant, mixed) defined by stool form. The diagnosis is one of exclusion.
• Surgery for IBS is not indicated, but patients with IBS frequently have undergone one or more surgical procedures in an attempt to alleviate chronic pain.
• Treatment of IBS depends on the subtype.
• There are three subtypes of chronic anal pain defined by Rome IV criteria: levator ani syndrome, unspecified functional anorectal pain, and proctalgia fugax, distinguished by pain duration and the presence/absence of anorectal tenderness.
• Coccygodynia is pain or discomfort at or around the coccyx, related to trauma or idiopathic.
• Pudendal neuralgia produces knifelike pain in the anus, vagina, or perineum, felt to arise from pudendal nerve entrapment in Alcock's canal or the infrapiriformis canal.

Filing

• Irritable Bowel Syndrome (IBS) — entirely new condition page. Rome IV definition/subtyping, diagnostic workup by subtype, the surgery-IBS relationship (misdiagnosis-driven cholecystectomy/ hysterectomy/appendectomy; diverticulitis/SUDD overlap; post-surgical new-onset IBS), and the full graduated treatment ladder (conservative → dietary/FODMAP → pharmacotherapy by subtype → neuromodulation → psychological/multidisciplinary).
• Functional Anorectal Pain & Coccygodynia — entirely new condition page, superseding and substantially expanding the brief "Anorectal pain" section previously carried on Fecal Incontinence. Covers the chronic-pelvic-pain framing, the three Rome IV functional anorectal pain subtypes (levator ani syndrome, unspecified functional anorectal pain, proctalgia fugax) with their treatment ladders (digital massage, biofeedback, EGS, Botox, sphincterotomy for familial proctalgia fugax), and coccygodynia (subtypes, workup, nonoperative and surgical treatment).
• Pudendal Neuralgia — entirely new condition page. Anatomy of entrapment (piriformis/sacral hypogastric fascia space, interligamentary space, Alcock's canal, subpubic dorsal nerve canal), Nantes diagnostic criteria, and the full treatment ladder (nerve block, neuromodulation incl. pudendal and conus medullaris stimulation, nerve ablation, fat grafting, and multiple named operative decompression techniques with outcome data).
• Fecal Incontinence — "Anorectal pain" section reconciled: replaced with a brief summary plus cross-reference to the new Functional Anorectal Pain & Coccygodynia page for full detail; the page's "Open items" note about diagnostic algorithms/management being deferred to "Chaps. 55–59, 65" updated to reflect that Ch56 (this chapter) now supplies that detail for the anorectal-pain slice of that deferral, while sphincteroplasty/sacral nerve stimulation protocols for incontinence itself remain deferred to still-later chapters.

Relevance

A useful chapter for a colorectal practice specifically because it foregrounds the surgery-avoidance message: patients with IBS and chronic pelvic pain are often referred to or land on a colorectal surgeon's schedule after a cascade of prior (frequently unnecessary) surgery, and the chapter's central practical contribution is a structured, subtype-driven medical/psychological treatment ladder that a surgeon can apply or triage from before further invasive workup. The diverticulitis-SUDD (symptomatic uncomplicated diverticular disease) overlap with IBS is a direct, practically relevant cross-reference to Diverticulitis that the existing wiki page did not previously carry. The pudendal neuralgia section is unusually procedural for a "functional disorders" chapter — it catalogs several named operative decompression techniques (Istanbul technique, operative pudendoscopy, Hibner repeat decompression) that are more surgery-adjacent than the rest of the chapter's conservative/medical focus.

Open items / gaps

• 98 references total; content is textbook-level/secondary throughout.
• Several individual RCTs/cohorts cited with quantified outcomes are flagged in Research Priorities.md as independent-verification candidates: the Ford et al. 2018 ACG IBS management monograph, the Black et al. 2020 secretagogue network meta-analysis, the Chiarioni et al. 2010 biofeedback-vs-EGS-vs-massage trial for levator ani syndrome, the Robert et al. 2005 pudendal nerve decompression RCT, and the Kleimeyer et al. 2017 coccygectomy-vs-nonoperative retrospective cohort.
• Chapter 57 ("Common Tests for the Pelvic Floor") begins immediately at PDF page 967 — next in the sequential ingest. Its offset should be independently reconfirmed via the copyright-line method rather than assumed to continue at +12, given that the +12 offset itself arrived via an unexplained +2 jump at this Part boundary rather than the usual +1 chapter-to-chapter drift.