Role of MRI Defecography in Diagnosis of Obstructed Defecation Syndrome

  • End date
    Jul 24, 2023
  • participants needed
  • sponsor
    Alshimaa Abdalkreem
Updated on 24 January 2021


The aim of the study was to assess the advantages of dynamic magnetic resonance imaging defecography to elucidate the underlying anatomic and pathophysiologic background in obstructed defecation patients to guide physicians in patient management.


Obstructed defecation syndrome (ODS) is a term used to describe the whole complex of mechanical and functional disorders leading to difficult or inadequate rectal emptying. obstructed defecation syndrome has prevalence rate 3.4 % in general population, In obstructed defecation feces do reach the rectum, but rectal emptying is extremely difficult. These patients have a feeling that defecation is blocked. Despite repetitive attempts, complete evacuation of rectal contents is not possible. The patients may also complain of prolonged and unsuccessful straining at stools, feelings of incomplete evacuation, digital removal of feces, and laxative abuse.

Constipation caused by obstructed defecation is of two basic types: functional and mechanical. The functional type includes anismus (pelvic floor dys-synergy), and descending perineal syndrome, whereas the mechanical type includes rectocele, enterocele, internal intussusception and overt rectal prolapse.

All of these conditions represent either a defect of pelvic support or abnormal function of the pelvic floor musculature. The etiology of ODS is controversial. It is presumed that in childbearing women damage to the innervation and soft tissues of the pelvis may occur as a direct consequence of vaginal childbirth. Trauma to the pelvic soft tissues can result in endopelvic fascial and pelvic support defects. Cumulative nerve damage from stretching of pelvic floor due to childbirth and activities that cause chronic and repetitive increases in intra-abdominal pressure such as obesity and chronic cough have been suggested to play a role in the development of symptomatic defects.

Although patients frequently complain of constipation, symptoms such as fruitless straining and incomplete evacuation are rather subjective and unreliable. Nevertheless, an international team of experts included these symptoms in the definition of constipation.This Rome III guidelines, for a patient to be labeled as suffering from functional constipation, which also includes obstructed defecation, following criteria should be present for at least 3 months:

  1. Must include two or more of the following:
  2. Straining during at least 25% of defecations,
  3. Lumpy or hard stools in at least 25% of defecations,
  4. Sensation of incomplete evacuation for at least 25% of defecations,
  5. Sensation of ano-rectal obstruction/ blockage for at least 25% of defecations,
  6. Manual maneuvers to facilitate at least 25% of defecations (e.g., digital evacuation, support of the pelvic floor),
  7. Fewer than three defecations per week.
  8. Loose stools are rarely present without the use of laxatives.
  9. Insufficient criteria for irritable bowel syndrome. The same criteria define dys-synergic defecation as inappropriate contraction of the pelvic floor or less than 20% relaxation of basal resting sphincter pressure with adequate propulsive forces during attempted defecation .

On physical examination, the paradoxical contraction of the pelvic floor can be assessed by palpation of the puborectalis muscle while the patient is straining . Perineal descent >3 cm, mucous discharge or mucosal prolapse may also be seen when the patient is asked to strain for stools . However, most clinicians do not rely on palpation and advocate the use of specific tests to diagnose ODS . Electromyography (EMG) of the pelvic floor, the balloon expulsion test (BET), and defecography are the most frequently used tests. Other radiologic methods for the dynamic evaluation of the ODS include magnetic resonance imaging and ultrasonography, each of which has its advantages and limitations.

The development of fast Magnetic Resonance Imaging sequences provides a new alternative to study all pelvic visceral movements in a dynamic fashion. MR defecography has several important advantages over conventional defecography. Its non-ionic nature, multiplanar capacity, dynamic evaluation and good temporal resolution along with its high-resolution soft-tissue contrast makes it an ideal modality in the assessment of ODS patients. Imaging in the mid-sagittal plane allows evaluation of the anal canal, anorectal angle, levator muscle and hiatus and the vaginal disposition as well as their relationship to a consistent electronically designated pubo-coccygeal Line (PCL). Diagnostic parameters for pelvic dys-synergy include an indented impression of the pubococcygeus muscle on the rectum with excessive obtuse anorectal angulation accompanied by very prolonged rectal emptying on T2-weighted MR images.

Condition MRI Defecography, ODS, MRI Defecography, ODS, MRI Defecography, ODS
Treatment MRI
Clinical Study IdentifierNCT03841006
SponsorAlshimaa Abdalkreem
Last Modified on24 January 2021


Yes No Not Sure

Inclusion Criteria

Patient group: Those with provisional diagnosis of obstructed defecation disorder based on: History by using Rome III criteria. and Physical examination
asymptomatic group: will be matched with patients for age and sex

Exclusion Criteria

Any general contraindication of MRI in some cases as presence of paramagnetic substance as pacemakers or in patients with claustrophobia
Clear my responses

How to participate?

Step 1 Connect with a study center
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer  to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact


Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider


Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note