Long-distance running can be one of the most empowering and exhilarating forms of exercise. However, for many runners, whether you’re training for a marathon or enjoying a weekend jog, there’s a not-so-glamorous side effect that can strike – sudden, urgent bowel movements commonly referred to as ‘runner’s trots.’
While it can be an awkward topic to discuss, it’s an issue that affects both new and experienced runners.
Here, we’ll explore what it is, why some people are more susceptible, and when it might be a sign to check in with a doctor.
Why gastrointestinal distress happens during long runs
No runner is immune to runner’s trots. When you’re covering long distances, your body diverts blood flow away from the digestive tract to fuel muscle activity. This reduced blood supply, coupled with the jostling motion of running, can irritate the bowels and speed up your digestive process. One study of Belfast City Marathon runners found that 83% of the (471) questionnaire respondents experienced one or more GI disturbances during or after running. The urge to have a bowel movement (53%) and diarrhoea (38%) were the most common symptoms.
Factors like diet, hydration, and stress can play significant roles in triggering toilet urges. Consuming high-fibre meals or rich, fatty foods too close to a run can exacerbate symptoms by making your gut work overtime when it’s already under strain. Dehydration can further irritate the intestines and disrupt normal bowel function, as can the surge of adrenaline that can accompany high-stakes events like a marathon.
Like most bodily processes, bowel habits vary from person to person. If you have a history of digestive sensitivities, whether it’s IBS (irritable bowel syndrome), lactose intolerance or other food sensitivities, you may be more prone to runner’s trots.
It’s worth noting your specific triggers, which can be anything from coffee to a high-carbohydrate sports gel, so you can plan your pre-run meals and snacks wisely.
Prevention and management tips
Just as you wouldn’t start a marathon without training, it’s important to prepare your digestive system for long-distance running. Timing your meals is key. Giving yourself a comfortable window, usually two to three hours, between your last substantial meal and the start of your run can allow digestion to settle.
Some runners find success with smaller, easily digestible snacks like bananas or low-fibre energy bars, for a final energy boost just before heading out.
Hydration is equally important. Your gut relies on adequate fluid levels to function properly, but too much liquid right before you run can provoke stomach issues. Striking the right balance may take some experimentation. Monitor how your body responds to different volumes of water or electrolyte drinks during runs. Most runners can comfortably handle 30–45 grams of carbohydrate per hour, although this can vary so it’s always a good idea to practice your fueling strategy before any big events.
For some runners, incorporating bathroom breaks into their route or waking up earlier on race day to give the body time to find its ‘rhythm’ can help. Pre-race nerves are normal, but heightened anxiety can speed up digestion. Techniques like deep breathing, mindfulness, or gentle dynamic stretches before the run may help keep your nerves – and your gut – in check.
When to get checked
If you’re experiencing chronic diarrhoea, intense abdominal cramping, or noticing blood in your stools, it’s essential to consult with a doctor. These symptoms may point to inflammatory bowel diseases or other gastrointestinal concerns that benefit from early diagnosis and targeted treatment.
If you’re experiencing any ongoing digestive issue, schedule an appointment with Mr Michael Stellakis.
