This document discusses obstructed defecation syndrome (ODS). It defines ODS as difficulty evacuating the rectum that may be associated with constipation. Common causes include diet, medications, and pelvic floor disorders. ODS is caused by abnormal function of muscles involved in defecation or anatomical abnormalities of pelvic organs. Diagnosis involves questionnaires, tests like defecography, and the ODS score. Treatment depends on the underlying cause and may include conservative options, biofeedback, or surgical procedures like STARR to repair defects.

1. Dr. Nabarun Biswas
(FCPS Surgery)
Registrar
Mymensingh Medical College Hospital

2. What is ODS ?
“ Difficulty in evacuation, which may or
may not be associated with constipation“
“ Difficulty in evacuation or emptying the
rectum which may occur even with frequent
visits to the toilet and even with passing
soft motions”

3. What is Constipation?
“Constipation is a symptom, not a
disease characterized by infrequent
bowel movements, usually less than
3 stools per week or hard to pass”.

4. Common causes of
constipation
 Diet
 Medications
 Medical conditions
slow movement of stool within the colon, irritable
bowel syndrome, and pelvic floor disorders
 associated diseases:
hypothyroidism, diabetes, Parkinson's, celiac
disease, non-celiac gluten sensitivity, colon
cancer, diverticulitis, and IBD
 Psychological
 Congenital

5. Features of Constipation that
correlates with ODS

6. Pathophysiology of ODS
 ODS has been shown to be the result of an
abnormal function of the muscles involved in
defecation or an anatomical abnormality of the
pelvic organs
 ODS is a complex and multifactorial condition
which is often referred to as an “Iceberg
Syndrome”

7. Why Obstructed Defecation
occurs?
One review stated that the most common
causes of disruption to the defecation cycle
are associated with pregnancy and childbirth,
gynaecological descent or neurogenic
disturbances of the brain-bowel axis. Patients
with obstructed defecation appear to have
impaired pelvic floor function

8. Specific causes of Obstructed
Defecation
 Anismus and pelvic floor dysfunction
 Rectocele
 Rectal invagination/ intussusception
 Internal anal sphincter hypertonia
 Anal stenosis
 Fecal impaction
 Rectal or anal cancer
 Descending perineum syndrome

9. Correlation with ODS
Obstructed defecation is one of the cause of-
1. Chronic constipation
2. Incomplete evacuation of bowel
3. Chronic large bowel obstruction and
4. Tenesmus

10. Classification
Outlet obstruction can be classified into 4 groups
1. Functional outlet obstruction
2. Mechanical outlet obstruction
3. Dissipation of force vector
4. Impaired rectal sensitivity

11. 1. Functional outlet obstruction
 Inefficient inhibition of the internal anal
sphincter
 Short-segment Hirschsprung's disease
 Chagas disease
 Hereditary internal sphincter myopathy
 Inefficient relaxation of the striated pelvic floor
muscles
 Anismus (pelvic floor dys-synergia)
 Multiple sclerosis
 Spinal cord lesions

12. 2. Mechanical outlet obstruction
 Internal intussusception
 Enterocele
3. Dissipation of force vector
> Rectocele
> Descending perineum
> Rectal prolapse
4. Impaired rectal sensitivity
Megarectum
Rectal hyposensitivity

13. Signs and symptoms
 incomplete or unsuccessful attempts to
evacuate
 prolonged episodes on the toilet
 rectal pain
 posturing
 digitations or perineal massage to aid
defecation
 enema dependency

14. Key features of obstructed
defecation
1. An inability to voluntarily
evacuate rectal contents
2. Normal colonic transit time

15. Five Questionnaire to diagnose &
grading ODS
1. Excessive straining?
2. Incomplete rectal evacuation?
3. Use of enemas and/or laxatives?
4. Vaginal-anal-perineal digitations (needing to
press in the back wall of the vagina or on the
perineum to aid defecation)
5. Abdominal discomfort and/or pain?

16. Diagnostic Approach for ODS

17. Dr Longo’s ODS Score

18. Interpretations
 Each point is scored according to frequency of
the symptom. Questions 1-6:
 0 =never, 1 = less than once weekly, 2 = 1–6
times weekly, 3 = every day; question
 7:0 = less than 5 min, 1 = 6 – 10 min, 2 = 11–20
min, 3 = more than 20 min; question
 8: 0 = no alteration of lifestyle, 1 = mild alteration,
2 = moderate alteration, and 3= significant
alteration of lifestyle.
 The total score is in the range of 0 (best) to 24.

19. Defecography
• Salient phases of Conventional / MRI
Defecography Image captured
– During rest with filled anal bulb
– During maximum contraction of anal
sphincter and pelvic floor muscles
– During straining without evacuation
– During evacuation
– During rest when evacuation is
completed

21. Management
Specific to the cause:
 Conservative:
 Dietary fiber
 Plenty of water
 Laxatives
 Rectal enema/ irrigation
 Biofeedback for anismus
 Psychotherapy
 Avoid chocolate and constipating
foods

22. Management
 Surgical treatment:
1. Manual technique
2. Stapled technique

23. Manual technique
I. to perform a kind of “surgical” irrigation;
II. to perform either a resection or a plication or
a pexy in case of internal mucosal prolapse;
III. to reinforce the rectovaginal septum and/or,
again, resect the redundant mucosa, in case
of significant rectocele; and
IV. to perform miotomy in case ODS is due to a
muscular disorder.

24. Stapled technique
STARR procedure

25.  Full thickness resection of the anterior rectum wall by stapler
after longitudinal stitches at 10, 12 and 2 o‘clock positions.
Similar approach at the posterior wall with stitches at 4, 6 and
8 o‘clock positions.
 Suturing of the overlapping dog ears at 3 and 9 o‘clock
positions.

26. Let’s see a video

27. Conclusion
ODS is a problem that is
frequently encountered in the
elderly females, and the
management should be tailor-
made to each clinical scenario.