Last week, a mother of a young man came in anguish to my clinic and asked me, “My son, aged about 21 years, once goes to the toilet, he won’t come out for an hour or so, disturbing all of us as we are four members in the house and only one toilet. When I stressed to him to inform the reason, he said that he faced hell to pass the motion. Further, he has to exert stress to get rid of stools that come like pellets or stones after struggling for half an hour to one hour.
According to a study and review published in Alimentary Pharmacology and Therapeutics. Volume 63, Issue 6, March 2026, a prominent peer-reviewed medical journal that chronic constipation is a common bowel disorder characterised by unsatisfactory defecation that results from infrequent bowel movements, difficult stool passage, or both. It affects approximately 10 % of the global population, although prevalence varies among countries and the diagnostic criteria used. Chronic constipation is commonly diagnosed using the symptom-based approach, according to which two or more of the given symptoms need to be present for the past three months, such as hard or lumpy stools, straining, a sense of incomplete evacuation, use of manual manoeuvres to facilitate stool passage, a sense of anorectal obstruction, and having less than three bowel movements per week. However, people with constipation also report a wide range of other symptoms, such as no sensation of needing a bowel movement and frequent toilet trips without a successful bowel movement that are burdensome and often require clinical care. Chronic constipation negatively affects patients’ quality of life and also leads to a considerable financial burden to patients and healthcare systems.
There are several treatment strategies for constipation, including dietary and lifestyle, pharmacological and behavioural treatments, and, more rarely, surgery. However, despite these, patients still report high dissatisfaction rates over the treatment options available to them, primarily due to inadequate relief of their symptoms, emphasising the need for better access to evidence-based and effective management strategies. Diet plays an important role in the management of chronic constipation and offers a cost-effective treatment strategy, compared to laxatives. Several randomized controlled trials have been conducted investigating the effect of nutritional supplements, foods, drinks, and whole diets in chronic constipation. Indeed, many clinical guidelines currently include dietary recommendations as a first-line management strategy, although they primarily focus on increasing fibre intake. Therefore, it is unclear whether the clinical guidelines represent the current evidence base. This review comprehensively examines the current evidence on the dietary management of chronic constipation and the dietary recommendations presented in clinical guidelines for chronic primary constipation.
Dietary management
The research evidence shows the dietary management of chronic constipation with dietary supplements and fibre supplements. Fibre is a very common over-the-counter treatment strategy that people with chronic constipation choose to use it. Fibre includes all carbohydrates that are neither digested nor absorbed in the small intestine and have a degree of polymerization of three or more monomeric units, plus lignin. Lignin is an insoluble dietary fibre component found in the cell walls of plants that acts as a natural, bulk-forming agent to treat constipation. It works by resisting digestion in the small intestine, increasing stool bulk, and stimulating the bowel to pass waste more quickly. The physicochemical properties of fibre, such as solubility, viscosity, and fermentability, determine its mechanisms of action in the bowel and, thus, its ability to modify gut motility and improve constipation. The soluble, viscous fibres result in a stool softening effect by retaining water and creating a viscoelastic substance in the colon, thereby increasing stool bulk. Insoluble, non-viscous fibres help in a mechanical stimulation of the gut mucosa, which may result in a faster gut transit time. Fermentable fibres can lead to the production of fermentation by-products, such as SCFA, that may stimulate gut motility and may also increase stool weight by increasing microbial mass. Therefore, different types of fibre are expected to exert different effects on constipation.
A systematic review and meta-analysis involving 1251 people with chronic constipation found that fibre supplements resulted in a significantly higher response to treatment and stool frequency compared to control subjects. However, subgroup analyses showed that the effects differed based on the type of fibre used. Psyllium supplements, a soluble and viscous fibre, were consistently shown to lead to significantly higher response to treatment and stool frequency, softer stool consistency and lower straining. Psyllium, or isabgol, is a natural, soluble fibre derived from the seeds of the Plantago ovata plant. Commonly used as a bulk-forming laxative to treat constipation and diarrhoea, it works by forming a gel-like substance in the intestines that aids digestion and, when combined with water, eases bowel movements. Beyond constipation relief, the other health benefits are that it helps manage cholesterol levels, improves glycaemic control for diabetes, and aids in weight management by promoting satiety.
Foods with Similar High-Fiber
While they do not contain psyllium, these foods have similar nutritional benefits soluble fibre to psyllium supplements: Fruits such as apples contain pectin, a soluble fibre, pears, bananas, and citrus fruits, oranges, grapefruit and vegetables like carrots rich in pectin, sweet potatoes, broccoli, and brussels sprouts also seeds, alike flaxseeds, rich in mucilage and chia seeds. Grains like Oats, oatmeal, and barley, as well as legumes such as beans, lentils, and peas. Similarly, inulin-type fructan supplements, a soluble and fermentable fibre, softened stool consistency, but had no impact on stool frequency. However, polydextrose and galacto-oligosaccharide supplements did not improve any constipation outcomes; such contrary results are likely due to differences in the fibres’ physicochemical properties, but also the mode of administration.
Role of water intake
Drinking water is crucial for preventing and managing constipation because it hydrates the colon, softens stool, and aids in the digestion of fibre. Adequate water intake prevents the colon from absorbing too much moisture from waste, which causes dry, hard stool that is difficult to pass.
Water helps to create softer, bulkier stools that are easier to pass through the digestive tract. Also, high-fibre diets require adequate water to function; without enough water, fibre can actually increase constipation. Proper hydration supports the smooth muscle contractions (peristalsis) in the intestines necessary to move stool. Dehydration is a leading cause of chronic constipation.
According to studies, mineral water containing magnesium sulphate is particularly effective, and it is advised to have an intake of 8 to 12 cups of fluid per day. It is always wise to drink fluids consistently throughout the day rather than in large, sudden amounts. It is found that warm water or tea in the morning may help stimulate bowel movements. One should limit caffeine and alcohol, as they can contribute to dehydration. (To be concluded).
