Obstructive Defecation Syndrome (ODS) is a generic term that refers to the difficulty in satisfactorily emptying the rectum during the process of defecation. The examination of patients with ODS shows that there are anatomical and functional pelvic alterations in variable connection with each other, as well as in relation to the symptomatology they reflect. The diagnosis and treatment of this pathology requires experts in General Surgery and Coloproctology to direct in a protocolized way the treatment of this heterogeneous pathology.
Chronic constipation is one of the most common reasons for consultation to primary care physicians, internists, gastroenterologists and colorectal surgeons.
ODS is a term of wide application, as it refers to the patient’s perceived inability to empty the rectum normally and is classified as a type of chronic constipation of the functional type. There are many additional terms (distal constipation, voiding dysfunction, obstructive defecation syndrome, etc.), which are used throughout the scientific literature to describe the same constellation of findings.
Who is usually affected by Obstructive Defecation Syndrome?
It is estimated that more than 15% of multiparous women have some type of pelvic floor disorder and that 10-20% of these patients will consult for voiding dysfunction. Some degree of obstructive defecation is seen in 50% of patients consulting for constipation.
How does Obstructive Defecation Syndrome manifest itself?
Patients affected by ODS usually report a mixture of general symptoms, such as:
- The perception of difficult rectal evacuation, with prolonged defecatory straining.
- The need for excessive straining.
- The sensation of incomplete or fragmented bowel movements.
- The desire to repeat bowel movements.
- The perception of pelvic heaviness or discomfort.
- The sensation of pelviperineal bulging.
- Sensation of anal blockage.
- The need for digital self-maneuvers to facilitate defecation (vaginal pressure, perineal pressure and direct fecal extraction).
- Anal soiling.
What are the causes of Obstructive Defecation Syndrome?
The clinical presentation of ODS can be divided into two main groups: mechanical dysfunction or obstruction (rectocele, enterocele, peritoneocele, peritoneocele, sigmoidocele, intussusception, rectal prolapse and perineal hernia) and functional dysfunction or obstruction (abdomino-pelvic dyssynergia, defecation dyssynergia or anismus). These forms may occur in isolation, associated with each other and/or with other types of functional constipation or not.
How to identify Obstructive Defecation Syndrome?
ODS is a very heterogeneous entity that requires thorough, systematic and cautious questioning. An attempt should be made to identify the main cause of the symptoms and prioritize the study based on it. Physical examination is also essential in the initial diagnosis of the patient.
In addition to the clinical criteria, the diagnosis of ODS requires the performance of functional studies to correctly characterize it. None of the functional tests are of definitive value in isolation, and their performance and results should be assessed in the context of the patient’s symptoms by a specialist with the ability to offer the most optimal treatment. Treatment will vary and may include lifestyle changes (increased fiber and water intake), drugs (different types of laxatives), physical therapies (biofeedback and pelvic floor rehabilitation) and sometimes even colorectal surgery (ventral rectopexy, colposacropexy, etc).