350.4 📋 章末速蚘 Summary

350.4.1 🔑 䞀句話瞜結

IBS is most common functional GI disorder (10-15% prevalence globally, F > M 2:1)Rome IV criteria: recurrent abdominal pain ≥ 1 day/week × 3 months + 2+ of (related to defecation, change in stool frequency, change in stool form); symptom onset ≥ 6 monthssubtypes by Bristol Stool Scale: IBS-D (diarrhea, > 25% loose), IBS-C (constipation, > 25% hard), IBS-M (mixed both ≥ 25%), IBS-U (unspecified)pathophysiology multifactorialvisceral hypersensitivity + altered motility + altered microbiome (dysbiosis) + low-grade inflammation + brain-gut axis dysfunction + psychosocial stress + post-infectious IBS + genetic predispositiondiagnosisclinical + Rome IV + exclude alarm features (≥ 50 yo, weight loss, hematochezia, anemia, family hx GI cancer, nocturnal, persistent severe); fecal calprotectin (distinguishes IBD from IBS) + celiac serology (especially IBS-D) + TSHtreatment foundationeducation + reassurance + low FODMAP diet (most evidence) + lifestyle (stress, exercise)IBS-C medicationPEG + linaclotide (Linzess GC-C) + lubiprostone + plecanatide + tenapanor (Ibsrela NHE3 FDA 2019) + prucalopride (5-HT4)IBS-D medicationloperamide + rifaximin (Xifaxan 14-d course) + eluxadoline (avoid pancreatitis/cholecystectomy hx) + alosetron (women, REMS) + bile acid sequestrants for bile acid diarrheapain managementTCAs low-dose for IBS-D (amitriptyline 10-25 HS), SSRIs for IBS-C, antispasmodics (dicyclomine, peppermint oil), pregabalin/gabapentinpsychological therapiesCBT (most evidence) + gut-directed hypnotherapy + mindfulnessother functional GIfunctional dyspepsia (Ch348), functional constipation (slow transit / outlet dysfunction — biofeedback / normal transit), functional diarrhea, cyclic vomiting syndrome (migraine association, amitriptyline preventive), cannabinoid hyperemesis syndrome (heavy cannabis + hot shower relief — cessation cure), globus sensation, functional heartburn (Rome IV); 2024 emerging: microbiome modulation + FMT trials + gut-brain axis modulators。

350.4.2 💊 治療粟芁

  • dietlow FODMAP diet (Fermentable Oligosaccharides Disaccharides Monosaccharides And Polyols) 3 phases (restriction 4-6 wk → reintroduction → personalization) — most evidence; dietitian guidance helpful
  • IBS-C medicationspolyethylene glycol (PEG) first-line laxative, linaclotide (Linzess) guanylate cyclase C agonist, lubiprostone (chloride channel activator), plecanatide (GC-C), tenapanor (Ibsrela) NHE3 inhibitor FDA 2019, prucalopride (Motegrity) 5-HT4 agonist
  • IBS-D medicationsloperamide (mu-opioid receptor agonist symptomatic), rifaximin (Xifaxan) non-absorbed antibiotic 14-d course (TARGET-3 supports re-treatment), eluxadoline (mu-opioid + delta — avoid pancreatitis/cholecystectomy history), alosetron (5-HT3 antagonist women REMS program), bile acid sequestrants (cholestyramine, colesevelam) for bile acid diarrhea
  • pain managementTCAs (amitriptyline 10-25 mg HS) for IBS-D especially, SSRIs for IBS-C especially, antispasmodics (dicyclomine, hyoscyamine, peppermint oil), pregabalin/gabapentin off-label visceral pain
  • psychologicalCBT (cognitive behavioral therapy — most evidence) + gut-directed hypnotherapy + mindfulness + acceptance commitment therapy
  • functional constipation outlet dysfunctionbiofeedback is effective treatment
  • cannabinoid hyperemesis syndromecessation curative + topical capsaicin + antiemetics + hot showers
  • cyclic vomiting syndrome preventiveamitriptyline, propranolol, topiramate (migraine-related)

350.4.3 🎯 盧醫垫的考前提醒

  1. IBS Rome IV criteriarecurrent abdominal pain ≥ 1 day/week × 3 months + 2+ of (related to defecation, change in stool frequency, change in stool form) — onset ≥ 6 months
  2. alarm features warranting workup≥ 50 yo new onset, weight loss, hematochezia, anemia, family history GI cancer, nocturnal symptoms → colonoscopy + comprehensive workup
  3. fecal calprotectin is key biomarker: distinguishes IBD (elevated > 250) from IBS (normal) — first-line screening
  4. low FODMAP diet is most evidence-based dietary intervention: 3 phases (restriction 4-6 wk → reintroduction → personalization); 50-75% improve with dietitian guidance
  5. IBS-C medications by mechanismlinaclotide + plecanatide (GC-C agonists), lubiprostone (ClC-2 activator), tenapanor (NHE3 inhibitor), prucalopride (5-HT4 agonist) — multiple options, individualize
  6. IBS-D medicationsrifaximin (Xifaxan, 14-d course) — non-absorbed; can re-treat per TARGET-3; eluxadoline avoid pancreatitis/cholecystectomy history (Viberzi REMS); alosetron REMS program (women only, ischemic colitis risk)
  7. TCA (amitriptyline 10-25 HS) for IBS-D pain — peripheral anticholinergic + central modulation; SSRIs for IBS-C — accelerate gut transit
  8. CBT (cognitive behavioral therapy) has strongest evidence for psychological intervention in IBS; gut-directed hypnotherapy also effective; gut-brain axis modulation
  9. cannabinoid hyperemesis syndrome (CHS)heavy chronic cannabis + cyclic vomiting + relief from hot showers/baths (pathognomonic) + cessation curative; topical capsaicin + antiemetics; growing recognition with legalization
  10. functional constipation subtypesslow transit + outlet dysfunction (pelvic floor dyssynergia — biofeedback effective) + normal transit — anorectal manometry + balloon expulsion + colonic transit study for evaluation