Motility, in full.

First exclude emergency/secondary causes (cauda equina/cord compression, fecal impaction with overflow) with a mandatory digital rectal exam, screen for eating disorder before dietary restriction, and classify the subtype (urge, passive, overflow, mixed) since it drives therapy. Work up loose-stool FI for inflammatory, infectious, and bile-acid drivers before labeling idiopathic. Manage with a stepwise ladder: optimize stool consistency (fiber, loperamide, bile-acid sequestrant, or TCA neuromodulator), pelvic floor PT plus biofeedback, skin protection and bridge devices, then escalate to surgical therapy. Prescribe the antimotility/neuromodulator agents with their indications, dosing, and safety limits: loperamide is first-line for loose-stool/urge FI, start low (e.g., 2 mg before meals or as needed) and titrate to stool consistency while staying within the FDA-approved maximum (8 mg/day OTC, 16 mg/day prescription), because the FDA warns that higher-than-recommended doses cause QT prolongation, torsades de pointes, and cardiac arrest; the TCA neuromodulator (e.g., amitriptyline, typically low-dose ~20 mg) is an off-label option reserved for loose-stool/idiopathic FI, and the AGS Beers Criteria recommend avoiding TCAs such as amitriptyline in older adults given their strong anticholinergic burden, sedation, orthostatic hypotension, and fall risk. Per the dedicated ASCRS 2023 fecal-incontinence guideline (updating ASCRS 2007, superseding reliance on ACG's broader 2021 anorectal-disorders guideline as the primary specialty source), sacral neuromodulation is a first-line surgical option for incontinent patients WITH OR WITHOUT a defined anal sphincter defect (conditional recommendation, low-quality evidence), it is not gated on documenting a sphincter defect. Sphincteroplasty remains appropriate for symptomatic patients with a defined external anal sphincter defect; repeat sphincteroplasty after a failed overlapping repair should generally be avoided in favor of other modalities. Antegrade continence enemas are an option before colostomy, which remains last resort.

Diagnosis: use a positive diagnostic strategy based on Rome IV criteria rather than a strategy of exclusion (strong for cost-effectiveness, high quality; consensus for time-to-therapy), and categorize by IBS subtype (consensus). In patients with IBS and diarrhea symptoms: check celiac serology (strong, moderate) and, in those WITHOUT alarm features, fecal calprotectin (or fecal lactoferrin) plus CRP to rule out IBD (strong; moderate quality for CRP/calprotectin, very low for lactoferrin). Recommend AGAINST routine stool testing for enteric pathogens (conditional, low) and AGAINST routine colonoscopy in patients younger than 45 without warning signs (conditional, low). Anorectal physiology testing only when symptoms suggest a pelvic floor disorder and/or for refractory constipation not responding to standard medical therapy (consensus). Treatment, all subtypes: soluble, not insoluble, fiber (strong, moderate); a LIMITED trial of a low-FODMAP diet (conditional, very low); gut-directed psychotherapies for global symptoms (conditional, very low); TCAs for global symptoms (strong, moderate); peppermint suggested (conditional, low); antispasmodics for abdominal pain (conditional, low); AGAINST probiotics (conditional, very low), AGAINST fecal transplant (strong, very low). IBS-C: chloride channel activators (strong, moderate) and guanylate cyclase activators (strong, high); AGAINST PEG products for global IBS-C symptoms (conditional, low); tegaserod reserved for women younger than 65 with ≤1 cardiovascular risk factor who have not adequately responded to secretagogues (strong/conditional, low). IBS-D: rifaximin (strong, moderate); alosetron only for women with severe IBS-D who have failed conventional therapy (conditional, low); mixed opioid agonists/antagonists, i.e. eluxadoline (conditional, moderate); AGAINST bile acid sequestrants (conditional, very low).

First exclude emergency/secondary causes (cauda equina/cord compression, fecal impaction with overflow) with a mandatory digital rectal exam, screen for eating disorder before dietary restriction, and classify the subtype (urge, passive, overflow, mixed) since it drives therapy. Work up loose-stool FI for inflammatory, infectious, and bile-acid drivers before labeling idiopathic. Manage with a stepwise ladder: optimize stool consistency (fiber, loperamide, bile-acid sequestrant, or TCA neuromodulator), pelvic floor PT plus biofeedback, skin protection and bridge devices, then escalate to surgical therapy. Prescribe the antimotility/neuromodulator agents with their indications, dosing, and safety limits: loperamide is first-line for loose-stool/urge FI, start low (e.g., 2 mg before meals or as needed) and titrate to stool consistency while staying within the FDA-approved maximum (8 mg/day OTC, 16 mg/day prescription), because the FDA warns that higher-than-recommended doses cause QT prolongation, torsades de pointes, and cardiac arrest; the TCA neuromodulator (e.g., amitriptyline, typically low-dose ~20 mg) is an off-label option reserved for loose-stool/idiopathic FI, and the AGS Beers Criteria recommend avoiding TCAs such as amitriptyline in older adults given their strong anticholinergic burden, sedation, orthostatic hypotension, and fall risk. Per the dedicated ASCRS 2023 fecal-incontinence guideline (updating ASCRS 2007, superseding reliance on ACG's broader 2021 anorectal-disorders guideline as the primary specialty source), sacral neuromodulation is a first-line surgical option for incontinent patients WITH OR WITHOUT a defined anal sphincter defect (conditional recommendation, low-quality evidence), it is not gated on documenting a sphincter defect. Sphincteroplasty remains appropriate for symptomatic patients with a defined external anal sphincter defect; repeat sphincteroplasty after a failed overlapping repair should generally be avoided in favor of other modalities. Antegrade continence enemas are an option before colostomy, which remains last resort.

Diagnosis: use a positive diagnostic strategy based on Rome IV criteria rather than a strategy of exclusion (strong for cost-effectiveness, high quality; consensus for time-to-therapy), and categorize by IBS subtype (consensus). In patients with IBS and diarrhea symptoms: check celiac serology (strong, moderate) and, in those WITHOUT alarm features, fecal calprotectin (or fecal lactoferrin) plus CRP to rule out IBD (strong; moderate quality for CRP/calprotectin, very low for lactoferrin). Recommend AGAINST routine stool testing for enteric pathogens (conditional, low) and AGAINST routine colonoscopy in patients younger than 45 without warning signs (conditional, low). Anorectal physiology testing only when symptoms suggest a pelvic floor disorder and/or for refractory constipation not responding to standard medical therapy (consensus). Treatment, all subtypes: soluble, not insoluble, fiber (strong, moderate); a LIMITED trial of a low-FODMAP diet (conditional, very low); gut-directed psychotherapies for global symptoms (conditional, very low); TCAs for global symptoms (strong, moderate); peppermint suggested (conditional, low); antispasmodics for abdominal pain (conditional, low); AGAINST probiotics (conditional, very low), AGAINST fecal transplant (strong, very low). IBS-C: chloride channel activators (strong, moderate) and guanylate cyclase activators (strong, high); AGAINST PEG products for global IBS-C symptoms (conditional, low); tegaserod reserved for women younger than 65 with ≤1 cardiovascular risk factor who have not adequately responded to secretagogues (strong/conditional, low). IBS-D: rifaximin (strong, moderate); alosetron only for women with severe IBS-D who have failed conventional therapy (conditional, low); mixed opioid agonists/antagonists, i.e. eluxadoline (conditional, moderate); AGAINST bile acid sequestrants (conditional, very low).