The modern standard of sitting on a toilet at a 90-degree hip angle is a recent invention that conflicts with the body’s natural mechanics for efficient elimination. Historically, the preferred posture for defecation has been a deep squat. The “best position” seeks a posture that reduces muscular strain and improves the efficiency and completeness of bowel movements. Understanding the anatomy clarifies how certain postures impede or facilitate waste removal.
The Anatomy of Optimal Elimination
The body maintains continence via the puborectalis muscle. This sling-like pelvic floor muscle wraps around the rectum, pulling the large intestine forward. This pull creates a sharp bend, known as the anorectal angle, between the rectum and the anal canal.
When standing or sitting, the puborectalis muscle is in constant contraction. This keeps the anorectal angle acute, kinking the passageway shut and preventing the unintended passage of stool.
Defecation requires the voluntary relaxation of this muscle to straighten the angle and open the passage. If the muscle does not relax sufficiently, the body compensates by increasing intra-abdominal pressure, which is referred to as straining.
Comparing Sitting and Squatting Postures
The standard sitting position maintains a 90-degree hip angle, only partially relaxing the puborectalis muscle. The anorectal angle remains acute, creating a kink in the passageway. This partial opening often necessitates straining to force the stool past the obstruction. Studies show that sitting takes significantly longer for satisfactory emptying compared to squatting.
In contrast, the full squatting posture draws the knees up toward the torso, positioning the torso at a much more acute angle (around 35 degrees). This deep hip flexion causes the puborectalis muscle to fully release its tension. The relaxation of this sling allows the anorectal angle to significantly widen, straightening the passage. Radiological studies show squatting increases the angle from approximately 100 degrees to around 126 degrees, facilitating easier passage and allowing for faster, more effortless elimination with less straining.
Practical Methods for Achieving the Optimal Position
Since most modern homes feature sitting toilets, the optimal position is achieved by elevating the feet to mimic the deep squat. The goal is to raise the knees above the hips, creating the acute angle necessary to relax the puborectalis muscle sling and straighten the anorectal angle.
A specialized footstool, often called a squatting stool, is the most common tool, designed to fit around the toilet base. These stools typically raise the feet by seven to nine inches, which is sufficient for anatomical alignment. Any stable object of the appropriate height, such as a sturdy box, can also be used.
Once the feet are elevated, lean the torso forward, resting the elbows on the knees if comfortable. Position the feet slightly wider than the hips for stability. This combination replicates the benefits of a full squat. Focus on deep breathing and relaxing the pelvic floor muscles, allowing the modified posture to straighten the elimination path.