A Harvard gastroenterologist has proposed a new three-part framework designed to help people understand and improve their bowel movements, tackling a subject that remains shrouded in unnecessary embarrassment.
Dr Trisha Pasricha, a physician-scientist at Beth Israel Deaconess Medical Center and assistant professor of medicine at Harvard Medical School, has developed the concept of the “three Ps of pooing”: propulsion, pliability, and pelvic floor. In her book, “You’ve Been Pooping All Wrong: How to Make Your Bowel Movements a Joy,” she argues that optimal digestive health relies on all three components working in harmony.
The need for clearer guidance is underscored by research from Symprove, which found a quarter of Brits wait a month before seeing a GP about digestive issues, while 84% admit they will only use their own toilet for a bowel movement. Many would rather endure discomfort for hours or days than use a public facility. “Patients come to my clinic, and they’re so mortified to put words to their problem,” Dr Pasricha notes, emphasising that understanding the mechanics can be “incredibly empowering”.
The Mechanics of Propulsion
The first ‘P’, propulsion, concerns the force that moves stool through the digestive system. This involves two key elements: involuntary contractions in the colon and a voluntary action known as the Valsalva manoeuvre—the brief ‘bearing down’ most people use on the toilet. “This raises the pressure in our chest and abdominal cavity, which then has nowhere else to go but downward,” Dr Pasricha explains.
Crucial to this process are High Amplitude Propagated Contractions (HAPCs), powerful involuntary waves that occur several times daily. They are particularly common in the first hour after waking and often follow eating, exercise, or drinking coffee, priming the body for a bowel movement. Ignoring this natural urge—due to embarrassment or inconvenience—can disrupt the process, leading to more straining, longer toilet visits, and an increased risk of conditions like haemorrhoids.
To support healthy propulsion, Dr Pasricha recommends establishing a routine, listening to your body’s signals, and making yourself comfortable enough to use unfamiliar toilets. Simple tips include carrying a mini toilet spray and listening to music. She cautions against prolonged phone use on the loo, however, as it can encourage unnecessary straining.
The Importance of Pliability
Pliability refers to stool consistency—how soft and easy it is to pass. The colon absorbs water from waste, and if it absorbs too much, stool becomes hard and difficult to move. This makes adequate hydration and fibre intake fundamental.
Adults should aim for 30g of fibre daily, sourced from fruits, vegetables, whole grains, nuts, and seeds. Increases should be gradual to avoid discomfort; if dietary intake is insufficient, a psyllium husk supplement can be considered. For hydration, NHS guidance suggests 6 to 8 cups or glasses of fluid per day, with water-rich foods like soups and produce also contributing.
A common mistake, Dr Pasricha says, is holding in stool even after improving diet. The longer waste remains in the colon, the more water is drawn out, undermining efforts to maintain pliability.
The Role of the Pelvic Floor
Often associated with bladder and vaginal control, the pelvic floor muscles are equally critical for bowel movements. They must relax at the right moment to allow stool to pass—a failure Dr Pasricha compares to trying to squeeze toothpaste from a tube with the cap still on.
Specialist pelvic health physiotherapist Rosie Cardale explains the mechanics: “One of the pelvic floor muscles (called the puborectalis) wraps around the rectum in a U shape. Usually this muscle is contracted, which keeps a 90 degree ‘bend’ in your rectum and keeps you continent. To poo, this muscle needs to relax, allowing the rectum to straighten.”
Position is therefore key. Squatting is considered optimal, but raising your knees above your hips using a footstool can mimic this while sitting. Strategic breathing can also help initiate a movement. Cardale suggests leaning forward, making a fist, placing your lips against it, and taking three long breaths “as if you are blowing into a trumpet” to create helpful abdominal pressure.
For persistent issues, therapies like biofeedback—which uses equipment to provide real-time feedback on muscle function—can help retrain the pelvic floor. This technique is offered by specialists, including London-based pelvic health physiotherapist Lucy Allen, and is used for chronic constipation and incontinence.
Broader Health Implications and Medical Advice
While the framework focuses on daily function, the consequences of poor bowel health are significant. Chronic constipation has been linked to conditions ranging from haemorrhoids to more serious illnesses like chronic kidney disease, dementia, and Parkinson’s disease.
Emerging research into the gut-brain axis, a focus of Dr Pasricha’s work, explores potential links between gut health and neurodegenerative diseases. For instance, some research suggests Parkinson’s disease may begin in the gut’s enteric nervous system, and up to 80% of people with Parkinson’s may develop dementia.
While adjustments to propulsion, pliability, and pelvic floor function can resolve many issues, persistent problems—lasting more than a couple of months or accompanied by pain or bleeding—warrant a consultation with a doctor. As Dr Pasricha’s framework aims to demystify a vital bodily function, the underlying message is clear: breaking the taboo around digestion is a critical step towards better long-term health.