Hemorrhoids may be brought on by pregnancy, obesity, and receiving anal sex. But the main cause is straining during bowel movement. Straining increases the pressure in your abdomen, causing the veins that line your anus to swell. In hemorrhoid patients, those veins stay swollen and sometimes bleed. In theory, squatting might stave off hemorrhoids by making defecation easier, reducing the need to strain and decreasing abdominal pressure.
An Israeli doctor named Dov Sikirov tested this idea for a 2003 study published in Digestive Diseases and Sciences. He had several dozen patients defecate in each of three positions: sitting on a 16-inch-high toilet, sitting on a 12-inch-high toilet, and squatting over a plastic container. He asked his subjects to record how long each bowel movement took and rate the effort required on a four-point scale ranging from effortless to difficult. Sikirov found that, when squatting, subjects averaged a mere 51 seconds to move their bowels, versus 130 seconds when sitting on a high toilet. And as they moved from a sit to a squat, subjects were more likely to rate the experience as easier.
Then last year, a group of Japanese doctors extended Sikirov's findings by looking at what happens inside the body while people squat and sit. For a study published in the medical journal Lower Urinary Tract Symptoms, six subjects had their rectums filled with a contrast solution and then released the fluid from a squatting or a sitting position while being filmed with X-ray video. Image analysis showed that the anorectal angle increased from 100 degrees to 126 degrees as the subjects moved from a sit to a squat. The researchers also recorded abdominal pressure, and found that the subjects were straining less when they squatted.
