Poop Better: Gastroenterologists’ #1 Habit to Break

Chronic constipation affects a significant portion of the population, with around 16% of adults worldwide experiencing symptoms. For many, the search for relief often leads to exploring dietary changes and supplements. But what if a simple shift in habit could develop a substantial difference? Recent dietary guidelines from the British Dietetic Association, published in October 2025, pinpoint one key behavior to modify for improved bowel regularity: reducing ultra-processed food consumption.

The Rise of Ultra-Processed Foods and Gut Health

The guidelines, appearing in the Journal of Human Nutrition & Dietetics and Neurogastroenterology & Motility, represent the first evidence-based recommendations for managing constipation through diet, rather than medication. Eirini Dimidi, a lead author and registered dietician at King’s College London, noted that existing advice – “eat more fiber, drink more water” – is often vague and lacks robust research backing. The new recommendations aim to fill this gap with concrete, evidence-supported strategies.

While increasing fiber intake and hydration remain important, the guidelines emphasize the detrimental impact of ultra-processed foods on digestive health. These foods, characterized by ingredients not typically used in home cooking – such as emulsifiers, artificial sweeteners, and hydrogenated oils – have been linked to a range of health issues, including gut dysbiosis and impaired bowel function. Gut dysbiosis refers to an imbalance in the composition of the gut microbiome, the trillions of bacteria and other microorganisms that reside in the digestive tract.

What Defines an Ultra-Processed Food?

Determining whether a food is “ultra-processed” isn’t always straightforward. Generally, these foods undergo multiple industrial processes and contain ingredients rarely found in a typical kitchen. Examples include packaged snacks, sugary drinks, processed meats, instant noodles, and many ready-to-eat meals. They are often high in sugar, salt, and unhealthy fats, while being low in essential nutrients and fiber.

The British Dietetic Association guidelines suggest prioritizing whole, unprocessed or minimally processed foods. This includes fruits, vegetables, whole grains, lean proteins, and healthy fats. Incorporating three kiwis a day, along with rye bread, was specifically highlighted as beneficial for improving constipation symptoms.

The Evidence Behind the Recommendation

The guidelines were developed through a rigorous analysis of clinical trials evaluating the effectiveness of various dietary interventions for constipation. The authors assessed the quality of evidence and the consistency of findings across studies. While the exact mechanisms by which ultra-processed foods contribute to constipation are still being investigated, several factors are believed to play a role.

Firstly, ultra-processed foods are typically low in fiber, which is essential for adding bulk to stool and promoting regular bowel movements. Secondly, they can disrupt the gut microbiome, reducing the diversity of beneficial bacteria and increasing the abundance of potentially harmful species. This imbalance can impair gut motility – the movement of food through the digestive tract – and contribute to constipation.

certain additives found in ultra-processed foods, such as emulsifiers, have been shown to negatively impact gut barrier function, potentially leading to inflammation and digestive discomfort. Research published in Nutrients suggests that emulsifiers can alter the gut microbiota and promote intestinal inflammation in susceptible individuals.

Constipation: Defining the Problem and Recognizing Symptoms

Constipation is generally defined as having fewer than three bowel movements per week. Though, the experience of constipation can vary significantly from person to person. Common symptoms include hard or lumpy stool, straining during bowel movements, a sensation of incomplete evacuation, and abdominal discomfort.

When constipation becomes chronic – lasting for more than three months – it can significantly impact quality of life and may be associated with other health problems. In the United States, constipation accounts for nearly 2.5 million doctor visits annually, according to the American College of Gastroenterology. More serious symptoms, such as blood in the stool, fever, or vomiting, warrant immediate medical attention.

Beyond Diet: Other Strategies for Relief

While reducing ultra-processed foods is a crucial step, it’s important to remember that constipation is often multifactorial. Other lifestyle factors, such as physical activity, stress levels, and medication employ, can also contribute.

Increasing physical activity can help stimulate gut motility. Managing stress through techniques like yoga or meditation may also be beneficial. Certain supplements, such as psyllium, probiotics, magnesium oxide, and polyethylene glycol, have been shown to provide relief for some individuals, as noted by EatingWell and supported by research from EatingWell. However, it’s essential to consult with a healthcare professional before starting any new supplement regimen.

Foods high in soluble and insoluble fiber, like those highlighted by Johns Hopkins Medicine, can also play a role in promoting regularity.

What’s Next in Constipation Management?

The British Dietetic Association’s guidelines represent a significant shift towards a more holistic and evidence-based approach to constipation management. Further research is needed to fully elucidate the complex interplay between diet, the gut microbiome, and bowel function. Ongoing clinical trials are investigating the effects of specific dietary interventions and probiotic strains on constipation symptoms.

The authors of the guidelines emphasize the importance of personalized dietary recommendations, tailored to individual needs and preferences. Working with a registered dietician can help individuals identify and address dietary factors contributing to their constipation and develop a sustainable plan for improving gut health. Public health initiatives aimed at promoting access to affordable, whole foods and educating the public about the harms of ultra-processed foods are also crucial steps in addressing this widespread health concern.