Although 30-50% of constipated patients exhibit dyssynergia, an optimal method of diagnosis is unclear.
Recently, consensus criteria have been proposed but their utility is unknown.
Dr Rao and colleagues from Iowa, USA undertook a study to examine the diagnostic yield of colorectal tests, reproducibility of manometry and utility of Rome II criteria.
The researchers prospectively evaluated a total of 100 patients with difficult defecation using anorectal manometry, balloon expulsion, colonic transit and defecography.
The researchers had to repeat manometry for 53 patients.
The researchers noted that during attempted defecation, 30 showed normal and 70 showed 1 out of 3 abnormal manometric patterns.
In addition, 46 patients fulfilled Rome criteria and showed paradoxical anal contraction (type I) or impaired anal relaxation (type III) with adequate propulsion.
|64% of patients had slow transit, 60% impaired balloon expulsion and 37% abnormal defecography|
|Neurogastroenterology and Motility|
However, 34% showed impaired propulsion (type II).
The researchers found that 64% of patients had slow transit, 60% impaired balloon expulsion and 37% abnormal defecography.
Defecography provided no additional discriminant utility.
Evidence of dyssynergia was reproducible in 51 of 53 patients. Symptoms alone could not differentiate dyssynergic subtypes or patients.
The research group found that dyssynergic patients exhibited three patterns that were reproducible: paradoxical contraction, impaired propulsion and impaired relaxation.
Dr Rao concluded, "Although useful, Rome II criteria may be insufficient to identify or subclassify dyssynergic defecation."
"Symptoms together with abnormal manometry, abnormal balloon expulsion or colonic marker retention are necessary to optimally identify patients with difficult defecation."