The puborectalis muscle is a key structure within the pelvic floor. Puborectalis Syndrome, also known as non-relaxing puborectalis or pelvic floor dyssynergia, is a functional bowel disorder where this muscle fails to coordinate properly during a bowel movement. Instead of relaxing, the muscle either contracts or does not relax enough when a person attempts to defecate, creating an obstruction at the end of the digestive tract. The issue is not one of muscle weakness, but rather a failure of the muscle to perform its normal relaxation function at the correct time.
The Role of the Puborectalis Muscle in Normal Function
The puborectalis muscle is a U-shaped sling of muscle fibers that originates from the pubic bone and wraps around the junction of the rectum and the anal canal. At rest, this muscle is in a state of tonic contraction, which pulls the rectum forward toward the pubis. This creates a sharp bend, known as the anorectal angle, that functions as a mechanical barrier to help maintain fecal continence and prevent stool from leaking unintentionally.
For a normal bowel movement to occur, the puborectalis muscle must voluntarily inhibit its contraction and relax. This relaxation effectively straightens the anorectal angle, allowing the stool to descend more easily into the anal canal for expulsion. The muscle’s coordinated relaxation, alongside a drop in pressure within the anal sphincters, facilitates the smooth and unimpeded passage of waste from the body.
Causes and Underlying Risk Factors
The direct cause of Puborectalis Syndrome is the paradoxical contraction or insufficient relaxation of the puborectalis muscle during attempted defecation. This discoordination, termed pelvic floor dyssynergia, means the muscles are actively working against the effort to push stool out. The resulting sensation is often described as pushing against a closed door.
The exact initial trigger for this abnormal muscle behavior is often unclear, but it is considered an acquired behavioral disorder. Learned behaviors, such as chronic or suppressed straining over time, can lead to the body adopting the wrong muscle pattern for evacuation. Other contributing factors can include underlying neurological issues, a history of trauma, or concurrent psychological mechanisms like anxiety or depression.
Recognizing the Symptoms of Puborectalis Syndrome
The symptoms of Puborectalis Syndrome are focused on difficulty with bowel movements, which is often mistakenly diagnosed as standard chronic constipation. A person with this condition experiences chronic difficulty or prolonged time in passing stool despite a strong urge to go. The most common complaint is a feeling of incomplete evacuation, medically termed tenesmus, where the rectum does not feel fully empty after a bowel movement.
Patients frequently report excessive and non-productive straining. The obstruction caused by the non-relaxing muscle often leads to the need for manual maneuvers to assist the stool’s passage. This can involve digital assistance, such as pressing on the perineum or inserting a finger into the rectum to help facilitate evacuation. Pelvic pain may also occur, described as a dull, chronic ache or pressure sensation located high in the rectum.
Diagnostic Procedures and Confirmation
Diagnosis of Puborectalis Syndrome relies on a combination of patient history, physical examination, and specialized testing. The initial physical exam, specifically a digital rectal examination, is used to assess the tone of the pelvic floor muscles. During this exam, the clinician asks the patient to bear down as if having a bowel movement, and a paradoxical contraction or lack of relaxation of the puborectalis muscle can be felt.
Anorectal manometry is a common procedure that measures the pressure within the rectum and anal canal during rest and straining. This test reveals an abnormal pattern, such as an increase or no drop in anal pressure when the patient attempts to evacuate, which is the opposite of a normal, coordinated bowel movement. Defecography, which is a dynamic imaging study, uses a thick contrast medium to simulate stool and allows doctors to visualize the lack of anorectal angle straightening and the prolonged retention of the contrast material within the rectum during attempted evacuation.
Treatment and Management Strategies
The management of Puborectalis Syndrome centers on non-surgical interventions designed to retrain the pelvic floor muscles and correct the dysfunctional pattern. The primary and most effective treatment is biofeedback therapy, a specialized form of pelvic floor physical therapy. This therapy uses sensors placed in the anal canal to monitor muscle activity, providing visual and auditory feedback to the patient on a screen.
The goal of biofeedback is to teach the patient to coordinate an increase in abdominal pressure with the proper relaxation of the puborectalis and anal sphincter muscles. Sessions often include balloon expulsion training, where a water-filled balloon simulates stool, helping patients practice the correct relaxation sequence for complete evacuation. Specialized pelvic floor physical therapists also incorporate stretching exercises, relaxation training, and techniques to improve rectal sensory perception. Lifestyle modifications are supportive measures that include increasing dietary fiber and fluid intake, and using stool softeners.