How to Stop Diarrhoea After 50: A Dietitian’s Practical Guide

If you’re constantly planning journeys around toilet stops, skipping meals before leaving the house, or worrying whether you’ll make it in time, you’re not alone.

Many of the people I work with tell me they no longer trust their gut.

The good news is that there are practical steps that can help. Often, it’s not about following a restrictive diet. It’s about understanding the patterns that may be contributing to your symptoms.

In my previous article, Why do I keep getting diarrhoea after 50? Common causes and what you can do about it, we explored some of the reasons diarrhoea becomes more common after 50. In this article, we’ll focus on what you can actually do to help.

Start With Regular Meals to help diarrhoea

One of the most common things I hear in clinic is:

“I don’t eat before I go out because I don’t want to need the toilet.”

And honestly, I completely understand why. It makes perfect sense to think that if nothing goes in, nothing can come out. Unfortunately, our digestive system doesn’t work quite like that.

Your gut loves predictability.

Regular meals help regulate the gastro-colic reflex, the natural signal that moves food through the digestive system.

Aiming to eat 3 meals per day is a good place to start. Skipping meals can make the gut more sensitive and the gastro-colic reflex (the signal to move food along the gut) stronger. Grazing all day can also have a similar effect. Eating a large evening meal after a long period of not eating can result in food that is consumed quickly and potentially a high fibre load hitting the gut at once.

Is fibre making my diarrhoea worse?

Are you eating too much fibre at once?

Are you eating fibre consistently throughout the day or when you think about it, are you have large amounts of fibre at one meal in particular? Sometimes people front load their day and have all their fibre at breakfast time – wholegrain cereals, fruits, seeds and nuts and then nothing much for the rest of the day.  Spreading out your fibre throughout the day can be helpful.

Could you actually be eating too little fibre?

At the other end of the spectrum many people reduce the fibre in their diet thinking it will help their diarrhoea, when in fact not enough fibre can cause diarrhoea.   Incorporating oats, bananas and berries into your diet can be helpful in absorbing excess water and make your poo firmer. This is one reason why GPs sometimes recommend products such as Fybogel (psyllium husk). Soluble fibre can help absorb excess fluid and improve stool consistency.

Does the type of fibre matter?

For others the type of fibre (previously called insoluble fibre) found in wholegrain cereals, seeds, nuts and skins on fruits and vegetables can cause issues.  Cooked vegetables are often better tolerated.

As research continues in this field we are aware that fibre is more complicated than we previously thought on insoluble versus soluble. We now know that fibre can work in a more nuanced way and we tend to think about it in terms of fermentability and viscosity.

If you regularly eat large amounts of fruit and experience diarrhoea, it may be worth limiting yourself to around three portions of fruit per day and spreading them throughout the day to see whether this improves your symptoms. A portion of fruit is 80g.

Many people are surprised to find that foods they’ve eaten for years suddenly seem to affect them differently as they get older. If that sounds familiar, you may find my article, How digestion changes after 50 (And why foods suddenly affect you differently), reassuring.

Be careful with caffeine

If you are fond of a morning cuppa then maybe that could be playing a role too. Whilst coffee is known to contain beneficial polyphenols and antioxidants, caffeine stimulates the bowel and can speed up how quickly food moves through the digestive tract.

Of course it is not just coffee that contains caffeine, tea, some fizzy drinks, green tea and matcha all contain it too.  Caffeine can stimulate the bowel, speeding up the time food passes through the gut. This means there is less time for water to be reabsorbed, leaving some people rushing to the nearest bathroom.

Caffeine can also spike anxiety and interfere with sleep.

Caffeine remains in the body for up to 10 hours so it is worthwhile looking at when you have your last cup of the day as that 3pm pick-me-up could mean you are still awake at 1am. Sleep is one of the lifestyle factors that impacts your gut.

The good news is that you can still get the benefit of the antioxidants and polyphenols from the decaffeinated versions of drinks.

Red Flag Symptoms: When to seek medical advice

Although diarrhoea is often due to something relatively straightforward, persistent symptoms (lasting 3-4 weeks) should never be ignored. If you have any of the following I would recommend that you contact your GP.

• Blood in your poo
• Unexplained weight loss
• Having to get up during the night / being woken from your sleep to open your bowels
• Family history of bowel cancer
• Significant changes in bowel habits – either constipation or diarrhoea

Should I go low FODMAP to help my diarrhoea?

FODMAPs are a type of carbohydrate that when they arrive in the large intestine can lead to water getting pulled in causing diarrhoea.  They are also highly fermentable – hello wind and gas!

A low FODMAP diet is considered a second line treatment for IBS. It is a challenging and complex diet and not advised to be undertaken without the guidance of a Dietitian.

Whilst a low FODMAP diet can be highly effective for some people with IBS, it isn’t the first thing I recommend trying. Simpler strategies such as regular meals, adjusting fibre intake and reviewing caffeine often help first.

If you’d like to understand more about whether a low FODMAP diet might be right for you, you may find my article The best diet for IBS: What works and what to avoid from a Registered Dietitian helpful.

Don’t forget the importance of the Gut-Brain Connection

Whilst it is natural to think that diarrhoea must be caused by something you have eaten there are often a number of lifestyle factors that can lead to diarrhoea.

The brain and gut ‘talk’ to each other constantly using nerve and electrical messages delivered backwards and forwards via the Vagus nerve. These are impacted by sleep, stress and the anticipatory anxiety of social events and travel.

The primary job of your brain is to keep you safe. Although we’ve evolved, our nervous system hasn’t entirely caught up with modern life. It can trigger the same stress response whether you’re facing a genuine physical threat or worrying about making it to an important event on time.

Sometimes our nervous system behaves a bit like a smoke alarm. It doesn’t always distinguish between burnt toast and a house fire. It simply sounds the alarm, preparing your body to respond even when the “threat” is sitting in traffic or worrying about a family event rather than running from a sabre-toothed tiger.

This is known as the fight or flight response and increases the speed at which food goes through your gut. One of the first questions I ask my clients is, “When did it begin, or when did it get worse?” Often, they can pinpoint a period in their life when they were dealing with personal stresses or significant life changes. Even years later their ‘alarm’ system can remain stuck on high alert.

I often see symptoms flare:

• before holidays
• when travelling
• ahead of weddings or family events
• during stressful periods at work
• when caring responsibilities increase.

One of my previous clients as said:

“Fiona helped me understand that IBS isn’t just about food. Stress and mental health matter too.”

Check your fluid choices to reduce diarrhoea

One area that is often overlooked is the fluid in your diet. Whilst no one wants to be stuck on water for ever it is worthwhile considering what you are drinking. We have already looked at caffeine. Alcohol can irritate the gut in some people and may worsen diarrhoea symptoms, swapping alternative drinks for water is a good way to reduce your intake.

Also fresh fruit juices can deliver a large sugar load to the gut.  This is something I caution against for people who are cocktail lovers, it’s double whammy – alcohol AND fruit juice!

5 things you can start doing today to help your diarrhoea

Eat regularly – aim for 3 meals per day, each containing a source of carbohydrate, protein and fibre

Space your fibre out if you have a large volume at one meal.

Drink 6-8 cups of liquid per day – be mindful of caffeine, fizzy drinks, alcohol  and fresh fruit juice.  Picking decaffeinated versions are helpful

Look at lifestyle factors – be honest about your sleep patterns and stress levels. Techniques such as diaphragmatic breathing can help calm the nervous system and reduce the intensity of gut-brain signaling. There are plenty of free videos online demonstrating how to practise it.

You may find it helpful to keep a symptom diary as well as tracking what you are eating and drinking also note your sleep, stress, bowel habits and any other gastrointestinal symptoms.

Frequently Asked Questions about diarrhoea after 50

Is diarrhoea a normal part of ageing?

No. Digestive changes become more common as we age, but persistent diarrhoea shouldn’t simply be accepted as a normal part of getting older.

Can stress cause diarrhoea?

Yes. Stress and anxiety can speed up the movement of food through the gut via the gut-brain connection, worsening urgency and loose stools.

Should I stop eating fibre if I have diarrhoea?

Not necessarily. The type, amount and timing of fibre often matter more than cutting it out completely.

When to seek specialist help

One client came to see me after years of worrying about what she could and couldn’t eat, her diet becoming smaller and smaller. Meals and trips out became stressful and she no longer trusted her gut. By identifying a combination of dietary triggers, stress patterns and lifestyle factors, she gradually regained confidence.

“Before working with Fiona, I was terrified to eat because of diarrhoea, bloating, wind and severe abdominal pain. After working together, I’ve gained confidence with food, introduced more variety into my diet and learned how to manage my gut health long-term.”

If you’ve reached the point where you’re planning your life around your bowels, avoiding holidays, or saying no to invitations because you don’t trust your gut, please know that you don’t have to figure this out alone.

Many of the people I work with have already tried eliminating foods, taking supplements, and searching endlessly online for answers.

More often than not, there isn’t one single trigger. It’s the combination of food, stress, sleep, routine and lifestyle that needs unpicking.

Through my Gut R.E.S.E.T Method, we work together to identify what’s driving your symptoms so you can stop worrying about where the nearest toilet is and start enjoying life again.

If you’re ready to stop planning your life around your bowels and start trusting your gut again, book a free 15-minute discovery call to find out whether the Gut R.E.S.E.T Method is the right next step for you.

Fiona Brannigan, BSc (Hons) Human Nutrition & Dietetics, HCPC-Registered Dietitian, Full member of the British Dietetic Association
Fiona Brannigan is a UK-registered dietitian and founder of Inspirit Nutrition & Dietetic Consultancy, based in Ayrshire and working with clients across the UK. With over 25 years of experience, including more than two decades in the NHS,  Fiona has supported thousands of people to improve their health through nutrition.

Her expertise spans gut health, menopause nutrition, digestive disorders, neurological conditions, and rehabilitation following illness. Fiona is particularly passionate about helping adults aged 50+ regain confidence and control over their gut health, manage symptoms such as bloating, constipation, and diarrhoea, and enjoy food without fear or discomfort.

Fiona is regulated by the Health and Care Professions Council (HCPC) and is a member of the British Dietetic Association (BDA). She offers one-to-one consultations online and in person, using evidence-based nutrition and personalised support to help people feel their best at every stage of life.

Book a free discovery call to discuss your gut health goals or learn more about Fiona’s work