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Defecatory Disorders

Chronic constipation, fecal incontinence, and defecatory dysfunction are overlapping clinical syndromes rather than a strict hierarchy. They can coexist and share anorectal or pelvic-floor mechanisms, while constipation may also reflect colonic dysmotility and fecal incontinence may accompany diarrhea.[2][3] Defecation depends on coordinated anorectal and pelvic-floor function; in women with rectocele and obstructed defecation, both anatomy and function guide treatment selection.[1][2][3][9]

How the three conditions relate​

The cleanest way to organize the space is by what's symptomatic versus what's mechanistic:

  • Symptom-based view. Chronic constipation and fecal incontinence are the two major clinical presentations
  • Anatomical or functional view. Anorectal diagnostic frameworks organize evacuation, continence, pain and sensation; Rome V now lists dyssynergic defecation separately and adds rectal sensory diagnoses[4]
  • Defecatory dysfunction (dyssynergia or inadequate propulsion) is impaired rectal evacuation, recognized among chronic constipation phenotypes, and can coexist with fecal incontinence.[3][4][5]

Clinically useful consequence. any patient with either predominant symptom deserves a targeted look at the other. In one specialist retrospective cohort, 165/349 patients with FI (47%) had coexistent constipation, and dyssynergic defecation was more prevalent in those with mixed FI-MC than in FI alone.[5] In community-dwelling Japanese adults aged 75 or older, FI was more prevalent with constipation than without (18.3% versus 7.4%).[6] Up to 50% of patients with defecatory disorders have delayed colonic transit, which can be secondary to pelvic-floor dysfunction rather than a primary colonic-motility disease.[2]

Articles in this section​

  • Defecatory DysfunctionDyssynergia and inadequate propulsion; Rome IV/V context, targeted physiology/imaging, biofeedback and individualized options for persistent symptoms or structural disease.
  • Chronic ConstipationNormal-transit, slow-transit, and defecatory-disorder subtypes; pharmacologic management framed for the reconstructive pelvic surgeon; when constipation must be controlled before prolapse or continence surgery.
  • Fecal IncontinenceSphincter-deficient, overflow, and mixed phenotypes; OASIS, rectovaginal fistula, rectal prolapse, neuromodulation, and sphincteroplasty — with the handoff points to colorectal surgery made explicit.
  • Neurogenic BowelBowel dysfunction in spinal cord injury, multiple sclerosis, and spina bifida; bowel-program escalation from transanal irrigation through antegrade continence enema to colostomy.

Overlap phenotypes worth knowing​

PhenotypeDominant mechanismClinical cueFirst-line action
FI without constipationVariable: loose stool or urgency, external sphincter defect, pudendal neuropathy, or low anal resting/squeeze pressureLeakage without constipation; assess stool form and OASIS or radiation history, and use endoanal US when sphincter repair is consideredBegin dietary/medical measures to optimize stool consistency; for persistent FI consider PFPT/biofeedback, and if surgery is needed consider sacral neuromodulation or sphincteroplasty for a demonstrated external sphincter defect[3][5][7]
Overflow FIFecal impaction with liquid leakage around retained stool; dyssynergia is one possible contributorConstipation history, palpable stool on DRE, liquid seepageDisimpact and treat the cause of retention; reassess leakage[2]
FI mixed with constipation (FI-MC)Coexistent constipation and leakage; dyssynergia is more commonStraining, digitation, incomplete evacuation alongside leakageOptimize evacuation and stool form; biofeedback for demonstrated coordination dysfunction[5]
Defecatory dysfunction, pureDyssynergic contraction or inadequate rectal propulsionDifficult evacuation supported by examination and physiological testingAnorectal biofeedback therapy[8]
Slow-transit constipationColonic dysmotilityDelayed colonic transit on testing after assessment for outlet dysfunctionTreat coexisting dyssynergia first with biofeedback; for slow transit, start with an osmotic or stimulant laxative, then consider a secretagogue or prokinetic if symptoms persist[3]

Why this matters to the reconstructive pelvic surgeon​

  1. Posterior-compartment surgery. Rectocele repair in a patient whose underlying problem is dyssynergia is a structurally successful operation with a functionally disappointed patient. Assess simulated evacuation on DRE before rectocele repair; when dyssynergia is suspected, pair anorectal manometry with balloon expulsion testing, and consider defecography when structural trapping is suspected.[8]
  2. Anterior and apical repair. Address constipation and excessive straining during perioperative planning. These symptoms can impair recovery and satisfaction.
  3. Fecal incontinence in the urogyn clinic. FI frequently coexists with other pelvic floor disorders, and ASCRS recommends a history that characterizes its duration and severity .[7]

References​

1. Heitmann PT, Vollebregt PF, Knowles CH, et al. "Understanding the Physiology of Human Defaecation and Disorders of Continence and Evacuation." Nat Rev Gastroenterol Hepatol. 2021;18(11):751-769. doi:10.1038/s41575-021-00487-5

2. Bharucha AE, Knowles CH, Malcolm A. "An Evidence-Based Practical Review on Common Benign Anorectal Disorders: Hemorrhoids, Anal Fissure, Dyssynergic Defecation, and Fecal Incontinence." Gastroenterology. 2026;170(1):50-69. doi:10.1053/j.gastro.2025.07.031

3. Bharucha AE, Lacy BE. "Mechanisms, Evaluation, and Management of Chronic Constipation." Gastroenterology. 2020;158(5):1232-1249.e3. doi:10.1053/j.gastro.2019.12.034

4. Rao SSC, Bharucha AE, Carrington EV, et al. "Anorectal Disorders." Gastroenterology. 2026;170(6):1318-1346. doi:10.1053/j.gastro.2026.01.037

5. Inal B, Yan Y, Aziz A, Rao SSC. "Clinical Characteristics and Pathophysiology of Fecal Incontinence Mixed With Constipation: An Underrecognized Problem." Am J Gastroenterol. 2026;121(2):472-478. doi:10.14309/ajg.0000000000003532

6. Nakagawa H, Yamazaki H, Ozaka A, et al. "Association Between Constipation and Fecal Incontinence in Community-Dwelling Older Adults in Japan." J Am Med Dir Assoc. 2026;27(3):105581. doi:10.1016/j.jamda.2025.105581

7. Bordeianou LG, Thorsen AJ, Keller DS, et al. "The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Management of Fecal Incontinence." Dis Colon Rectum. 2023;66(5):647-661. doi:10.1097/DCR.0000000000002776

8. Wald A, Bharucha AE, Limketkai B, et al. "ACG Clinical Guidelines: Management of Benign Anorectal Disorders." Am J Gastroenterol. 2021;116(10):1987-2008. doi:10.14309/ajg.0000000000001507

9. Rachaneni S, Dietz HP, Latthe P, Sirany A, Spivak A, Dua A. "IUGA Opinion Paper on Obstructed Defecation: Management of Clinical and Proctographic Rectoceles." Int Urogynecol J. 2026;37(1):75-85. doi:10.1007/s00192-025-06288-7