Check your stools, know your health

I briefly mentioned the importance of bowel movement with regards to health in my last talk (Talk: Reversing chronic inflammation and balancing blood sugar with food). In here, I will elaborate further on this topic.

Food passes through our digestive tract with nutrients and fluids being absorbed along the way. Bowel movement refers to the last stop where the faeces or stools pass out of the body through the rectum and anus. Irregular bowel movements or unusual stools formation could be an indication of poor health or symptoms of specific illnesses. Hence, it is a good habit to observe your bowel movement habit if you want to take control of your health.

What should your stools look like?

The Bristol Stool Chart, as shown below, is commonly used to classify human stools [1].

Bristol Stool Chart (This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license)

Normal stools should be like type 3 or 4. Each piece should look like a sausage or snake with smooth or slight cracks on the surface. Anything that is lumpier and harder is an indication of constipation (type 1 or 2). In contrast, faeces will lack consistency (type 6 or 7) in diarrhea. If the stools consist of soft pieces that easily breaks, then you are not taking enough fibres in the diet. So, do observe the shape of your stools the next time you have a bowel movement. 

How frequent should you have bowel movements?

The frequency of bowel movement can be affected by many factors, including age, diet, exercise, lifestyle, and disease.  According to a study in America, most people (95.9%) reported between 3 times per week to 3 times per day [2]. Hence, the range of 3/week to 3/day is considered ‘normal’ in the general population. Those having less than 3 bowel movement are considered having constipation. Besides hard stools and infrequent bowel movement, constipation is often associated with difficulty and even pain when the passing stools [3].

It is better to have more frequent defecation than less. The time food stays in the digestive tract, as shown in the diagram above, is called transit time: slow transit time and constipation increase oxidative stress [4]. In fact, the longer the transit time, the lower the efficiency of the colon’s ability to produce the short-chain fatty acids (SCFCs). SCFCs are produced by bacteria in the gut through fermentation of fibres. It is a critical source of energy for colon cells. SCFCs also improve gut health by lowering oxidative stress and protecting against inflammation, which, in turn, reducing the risk of colorectal cancer [5]. So, it is best to keep to a bowel habit of at least once a day for good health.

What factors can cause infrequent bowel movement or constipation?

Diet is a crucial factor that affects how many times you poop a day. A high fibres diet will make bowel movement more frequent. A study in the United Kingdom found that vegetarians, especially vegans, have significantly higher bowel movement frequency than meat-eaters [6]. Another research which analysed the findings of multiple clinical trials on constipation found that increasing dietary fibres intake stool frequency consistently [7]. Clearly, eating more plant-based food will increase dietary fibres and promote healthy bowel movement. (Check out ‘Five foods that help to relieve chronic constipation‘ if you want to learn more.)

Vegetables are naturally high in dietary fibres – they are great for improving bowel movement!

Another factor is exercise. Moderate exercise, like jogging or cycling, helps to dramatically increase the transit time [8]. Physical inactivity can trigger flatulence and decrease of bowel movement [9]. As such, keeping an active lifestyle helps. However, exercise works better to improve constipation when one also increase the intake of dietary fibres [10].

Taking medication also increases the risk of infrequent bowel movement and constipation. Common painkillers such as aspirin, paracetamol (Panadol), and non-steroidal anti-inflammatory drugs are known to increase the chance of constipation [11]. Constipation is also a known side-effect for many medicines, including those help to manage blood pressure, incontinence, and allergy [12]. Not surprisingly, studies in a nursing home often found the increasing use of medication is a major risk associate with chronic constipation among older people [13,14].

Moderate exercise can help to improve bowel movement.

Many diseases can also cause constipation, such as inflammatory bowel disease, irritable bowel syndrome, hypothyroidism, diabetes mellitus, muscular dystrophy, and many more. Therefore, it is crucial to seek medical help if you suffer from chronic constipation, there may be some underlying cause to it. However, if the doctors cannot find any reason for it, then such constipation is known as ‘functional’ [15]. Functional constipation is linked to emotional and behavioural disorders, especially stress and anxiety [16].

What are the causes of too frequent loose stool or diarrhea?

A sudden increase in frequency with watery and loose stool is most likely caused by an infection. It can be a result of eating contaminated food that contains harmful bacteria. Hence, for children, learning and keeping hygiene practices at home and in school is essential to prevent diarrhea [17]. If you travel out of the country to an unfamiliar place, be careful of what you eat, you may develop diarrhea (See my post on Traveller’s diarrhoea: Natural remedies for prevention and self-treatment). Some infections can be chronic, which last for a long time and causing distress.

Eating the wrong type of food can also be a cause for frequent diarrhea if your body cannot take it. Lactose intolerance is a typical example. Many people are not aware that they cannot tolerate milk and milk products. In fact, as many as 65-70% of the world’s adults are potentially lactose and milk intolerance according to their genes [18]. Gluten sensitivity is another example. The body can be allergic to wheat and wheat-based products, or simply unable to digest gluten properly. The result is bloating, stomach discomfort, flatulence, and diarrhea [19]. The body can also disagree with many other types of food and even food additives. Hence, sometimes it is tough to detect the exact food that triggers intolerance. The only way is trial-and-error, that is, trying to avoid a specific type of food for sometimes to observe whether it improves bowel condition.

Like constipation, diarrhea can also be caused by diseases, including inflammatory bowel disease, irritable bowel syndrome, pancreatitis, celiac disease, or malabsorption syndromes [20]. Chronic diarrhea can also be functional with the doctors unable to find any specific physical cause. Emotional distress is also suggested as a likely cause for diarrhea [21].

Emotional distress can be a cause of diarrhea as well.


Keep tap of your bowel movement and stool type; they can tell you a lot about your health. Normal stools should look like sausages with smooth or slight cracks on the surface. It is advisable to have at least one bowel movement a day since shorter transit time can reduce oxidative stress and prevent inflammation. Having constipation or diarrhea can be a warning sign for health, especially if it is chronic. The exact cause of constipation or diarrhea may be complicated. Nevertheless, simple lifestyle changes such as increase fibres in diet, exercise moderately and reduce stress can definitely help.   


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