Food and slower transit may affect stool odor. Put changes in context and recognize NHS-backed symptoms that need medical attention.
On October 10, 2026, The Sun published doctors' explanations of why stool odor can change, including food and slower movement through the digestive system. Dr. Vijay Nayar of Healthium Clinics said an occasional foul-smelling bowel movement is typically not a cause for concern but a persistent change deserves more attention.
Before the October report, guidance from the NHS and Cleveland Clinic focused on bowel function and accompanying symptoms. That provides a different starting point from trying to interpret an unpleasant smell in isolation. The central questions concern what has changed and what else is happening.
NHS guidance gives attention to symptoms that continue or keep returning. It includes abdominal pain and bloating as well as blood or mucus in stool. This places an observation in the bathroom within the wider pattern of digestive health.
Cleveland Clinic describes constipation as potentially involving fewer than three bowel movements a week, hard stools or straining. Frequency is therefore only part of the description. Whether passing stool has become harder also matters when considering a change in bowel habits.
That clinical background is important when reading a headline about smell. A stronger odor may attract attention first, while a change in stool consistency or difficulty passing stool provides additional context. The established approach is to consider the pattern rather than make one feature carry the whole explanation.
The October report connects an everyday observation with two possible influences: food intake and digestive transit. Transit means how quickly material moves through the digestive system. Dr. Vijay Nayar told The Sun that both food and the speed of that movement can affect stool odor.
This gives readers a way to put a change into context. Alongside noticing the smell, consider whether eating habits or bowel habits have changed. Those observations reflect the influences described by the clinicians in the report.
The Sun lists high-protein foods and artificial sweeteners among possible contributors to changes in stool odor. It also mentions excessive vitamin intake. The relevant dietary context is therefore broader than the last meal someone remembers eating.
A useful description might include whether a food category has become more prominent or whether intake of a vitamin product has changed. These are details to note when reviewing the timing of an odor change. They keep the conversation grounded in what actually happened rather than a general impression that digestion feels different.
For that broader dietary context, reviewing the overall pattern of food and fiber intake offers a more organized starting point. The purpose here is to describe recent eating patterns alongside bowel changes, not to judge a food solely by the smell of the next bowel movement.
GP Maz Mwambazi of Nuffield Health told The Sun that constipation can leave stool in the gut for longer. Mwambazi described that extra time as allowing more fermentation and gas buildup. In that explanation, gas and bowel movements may develop a stronger smell.
The important connection is between time in the gut and the opportunity for fermentation. This is more specific than simply saying that constipation and odor sometimes occur together. It offers a possible explanation for why a change in bowel habits may coincide with a change in smell.
Cleveland Clinic's description helps put that explanation into everyday terms. A person reviewing the change would consider hard stools and straining as well as frequency. These details give the transit explanation a place within the wider account of bowel function.
The October coverage was a newspaper report built around clinicians' comments, not an announcement of a new clinical trial testing stool odor. Its explanations do not establish that a particular smell reliably identifies a disease. The report therefore adds context rather than a new diagnostic rule or dietary guideline.
The Sun also names lactose intolerance and fructose intolerance among possible contributors. Its infection warning concerns a sudden and distinct shift to an extremely unpleasant smell. These are reported possibilities, not conditions that can be distinguished from one another by smell alone.
The newspaper mentions gradually increasing fiber and drinking more water in its discussion of constipation. That general advice does not establish what is suitable for every individual. Personal decisions about dietary management, testing or treatment belong with a qualified healthcare professional.
With those evidence limits in place, the clearest practical guidance comes from the accompanying symptoms identified by the NHS and Cleveland Clinic.
NHS guidance advises contacting a GP about:
Cleveland Clinic also identifies blood in stool and significant unexplained weight loss as reasons to seek medical attention. These symptoms deserve attention regardless of whether stool odor has changed.
A persistent odor change accompanied by concerning bowel symptoms is a reason to discuss the overall pattern with a clinician. Describe the change in smell alongside the symptoms rather than presenting it as a diagnosis. Include any relevant changes in food intake or bowel habits identified in the report.
For additional context, DigestGenius's guide to recognizing when digestive symptoms need professional attention addresses the distinction between everyday observations and concerns that belong in clinical care.
The NHS says severe abdominal pain requires immediate action. The same applies to non-stop rectal bleeding or a large amount of blood or clots in stool. Seek immediate medical help for those symptoms rather than waiting to see whether the odor settles.
These are symptom-based warnings. They provide a clearer basis for action than trying to decide whether a smell seems unusual enough to be concerning.
The realistic dietary implication is modest: consider the context before making sweeping changes. An occasional stronger-smelling bowel movement fits the reassuring explanation Nayar gave The Sun. A lasting change accompanied by bowel symptoms calls for attention to the whole pattern.
The questions supported by the reporting are straightforward. Has food intake changed? Have bowel movements become less frequent or harder to pass? Did the odor change alongside diarrhea, pain or bloating? These are observations to bring to a conversation rather than answers about the cause.
A list of possible dietary contributors should not become an automatic list of foods to remove. The report describes several influences rather than identifying one food as the explanation for every reader. Decisions about restriction are better grounded in an individual's symptoms and professional assessment than in odor alone.
If constipation and fiber are part of that discussion, considering food tolerance when dietary patterns change can help frame the questions. The aim is to understand bowel function and eating patterns together, not to make a bowel movement smell a particular way.
The useful lesson from this coverage is one of proportion. Notice a change without treating every unpleasant smell as an alarm. Let persistence and accompanying symptoms guide the next conversation about food or care.
Interpreting a change in stool odor requires room for ordinary dietary variation without letting that reassurance obscure symptoms that deserve medical attention. DigestGenius makes educational articles and extended resources freely available to help adults distinguish established digestive evidence from emerging microbiome findings.
DigestGenius publishes research-led guidance on digestion, the gut microbiome, fiber, probiotics, gut-brain signaling, inflammation and everyday digestive wellbeing.
Explore clear, research-led guidance on digestion, the microbiome, food, fiber, probiotics and the gut-brain connection.
read the blog
