What is Constipation, Diarrhoea and Normal


Scientists desperately try to put values on body functions to measure and classify symptoms. This enables statistical comparisons to evaluate the effects of diseases and treatments. Defaecation is a good example of this and also of the influence of history, fashions and personal opinions.  For example, faeces are currently fitted into seven categories according to their appearance as shown in Table 1. Types 3 to 5 are considered ‘normal’. Types 6 & 7 indicate ‘diarrhoea’ and Types 1 & 2 are the result of slow movement through the colon giving ‘constipation’.  


1 Small separate hard lumps
2 Like lumps stuck together
3 Sausage shaped with cracks and lumpy surface
4 Soft sausage shaped, smooth surface
5 Soft blobs with definite shape
6 Mushy blobs
7 Watery with no solid parts

 ‘Normal’ performance as measured by the number of daily visits to the toilet has changed with fashion over the years. In the good old days when laudanum (opium tincture) was a favourite tipple, it’s constipating effects might have lead to the use of laxatives to meet a once-a-day ideal. A range is now recognised as normal – not more than 2-3 times a day but more than 2-3 times a week. Some writers suggest that after every meal is the ideal frequency, but people with this as a type of Irritable Bowel Syndrome (IBS) would certainly not agree.

Comparisons made between Western and African diets in the 1970s lead to an ideal faeces daily weight of 500g. This hardly seems achievable compared with the usual values shown in Table 2. Endemic dysentery does not appear to have been considered in the promotion of African values as the western goal. More recently, one English gastroenterologist has written that the passage of more than 200g of stool a day should be considered diarrhoea. This would include the effects of most vegetarian diets.


MEAT DIET 50 – 70
MIXED DIET 60 – 250

In the 1970s years of fibre frenzy it was suggested that not enough fibre was being eaten if faeces did not float. However undigested fat can have the same effect, so that theory did not last long.  

The problem is that colons don’t read text books, and even if their owners do, bowels don’t always do what is expected. Is ‘expectation’ part of the problem in deciding what is normal and what is not. Other body functions vary according to what is required and so will defaecation be influenced by lifestyle and eating habits. An upbringing trying to conform to standards such as daily performance may lead to greater use of laxatives which was sometimes encouraged by health professionals and still is in some ‘detox’ therapies of alternative medicine. Even in the 1972 trial of wheat bran for diverticular disease, the aim was a once-a-day visit to the toilet. By today’s definition, the frequency was normal even before the trialists started taking bran.  

The convenience of bowel habits is also important in deciding if treatment is needed. Frequent calls to stool in a morning is not a problem at home but devastating if setting out on a long journey or attending an important social function. Urgency and it’s opposite are not often mentioned, or quantified by the scientists. Finding public toilets is a problem for the mobile, the problem of urgency is magnified in the frail, arthritic or bed-bound. Most people would include frequent, urgent or accidents as diarrhoea. A long time needed for defaecation might be called constipation or contribute to this if inconvenient.  

The time taken for food to pass from mouth to anus is known as ‘transit time’ and can be measured in hours/days. This has been used to measure the effects of diets, treatments and diseases such as diverticular disease. Control groups, if they were used, could be student volunteers or people of the same age with other diseases and their drugs. Is this really a measure of normal? We know that eating more fibre produces a shorter transit time with larger, less dried stools. This could help reduce straining – another problem which cannot be quantified which people call ‘constipation’ More dietary fibre can change the appearance of faeces from Type 1 or 2 towards Type 6 or 7 (see Table 1). This is a normal physiological response to the extra work given to the colon, but even a healthy person has to decide when ‘normal’ changes to ‘diarrhoea’ If the colon is not functioning correctly and input exceeds output, then extra fibre could lead to pain, discomfort or bloating which would be considered ‘constipation’. Thus personal comfort becomes another critical factor in deciding what is ‘normal’ and nobody else can put a value on this.  

There are situations which do not fit in with the statistics and traditions.

             Passing small hard faeces 4 or 5 times a day is not diarrhoea but an indication of the bowel struggling to overcome constipation.

            Watery faeces with urgency when call to stool has been infrequent may not be diarrhoea but caused by hard and stuck faeces (impaction) with excess mucous           lubrication and a result of constipation.

           Drugs such as loperamide, sometimes taken before a social occasion can stop bowel movement for 1 or 2 days. Some people call this constipation. Catch-up day, with several visits to the toilet when the drug effects have worn off is sometimes referred to as diarrhoea. A migraine attack, even without head pain, can have the same effect.

          If the colon has been emptied by a bout of diarrhoea there may be no call to stool for 1 or 2 days until faeces build up again. Some people consider this period to be constipation.  

A survey was completed in 2001 by 230 people with diverticular disease (DD) which examined their interpretation of bowel habits. 95% of these people had pain but constipation was not the prominent and persistent characteristic so often attributed to DD. The majority had variable habits even when they considered themselves to have constipation, diarrhoea or were regular. (Table 3) This variation with DD is a great cause of difficulty in finding diets, treatments and lifestyle which provide predictability, stability and comfort. These variations and their interpretation are shown in the table.  


REGULAR 25 11% Nobody had frequency less than twice weekly, most were once daily. Only these people did not have type 1 faeces, most were like type 4. Straining reported by 3 people
CONSTIPATED 31 13% Nobody had frequency less than twice weekly, most were variable or daily. 3 people had type 7 and 11 had type 1 faeces, others were ‘normal’ 12 people had straining
DIARRHOEA 41 18% 1 person less than twice weekly, most were more than 3 times daily or variable frequency. 4 people had type 1 faeces, most were types 5 – 7. The was the only category with no straining
VARIABLE 133 58% 1 person less than twice weekly, 8 people daily, most were variable. Most varied between both extremes of faeces types. 42 people reported straining.

  Diarrhoea needs treatment when  prolonged and serious, non-infectious diarrhoea can be self-limiting. Constipation is best approached by long term prevention. What is meant by ‘constipation’ ‘diarrhoea’ or ‘normal’ appears to be a very personal interpretation. It is essential when consulting a health professional to make sure that both of you are talking about the same problem. Changes in habit, persistence or increase of symptoms, new symptoms such as fever, weight loss or bleeding from the back passage should be reported and investigated. Also consider that if laxatives and antidiarrhoea drugs regularly appear on your supermarket shopping list then perhaps professional advice is needed. 

© Mary Griffiths 2005 

NOTE This article appeared in Incontact Magazine Winter 2005/2006

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