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Colon· Chapter 13

IBS and Functional Bowel

Rome IV positive diagnosis, low-FODMAP Monash 3-phase, rifaximin retreatment criteria, eluxadoline (and the post-cholecystectomy contraindication), alosetron REMS, ATLANTIS TCA dosing for visceral hypersensitivity, and the CBT delivery channels the boards now recognize.

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31 MCQs2 podcast episodes
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    5-option vignettes with full wrong-answer teaching.
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What this chapter covers

  • Section 13.1: Definition and Rome IV diagnosis

    Irritable bowel syndrome is a positive clinical diagnosis built on a stereotyped symptom pattern, not a diagnosis of exclusion that emerges only after every organic possibility has been chased to ground.

  • Section 13.2: Pathophysiology

    IBS is a disorder of brain-gut interaction, and the pathophysiology is multifactorial because the symptom syndrome captures patients who arrive at the same final phenotype through different upstream mechanisms.

  • Section 13.3: IBS-C treatment

    IBS-C treatment is layered, and the layers correspond to escalating mechanism-targeted intervention.

  • Section 13.4: IBS-D treatment

    IBS-D treatment, like IBS-C, is layered, but the mechanisms targeted are different and several of the drugs carry meaningful safety considerations that the boards test directly.

  • Section 13.5: All-subtype treatments

    Several therapies work across IBS subtypes because they target shared mechanisms (visceral hypersensitivity, central pain processing, the brain-gut axis) that are not subtype-specific.

  • Section 13.6: Bloating and pharmacology summary

    Bloating is the symptom IBS patients report as most bothersome, and the boards split it into two ideas the candidate must keep separate.

Podcast episodes

  1. 01

    ROME IV Pathophys IBS C

    This episode covers the diagnosis and subtyping, the brain-gut mechanisms that explain why the disease behaves as it does, and the drugs for the constipation-predominant form.

  2. 02

    IBS D Neuromod Bloating

    This episode covers the diarrhea-predominant subtype, the treatments that work across subtypes, and bloating. The diarrhea-predominant and constipation-predominant patients share a disease label, but their drug options aren't parallel: the constipation drugs act on intestinal secretion, while the diarrhea drugs act on transit, the microbiome, bile acid...