Right consistency
The consistency of the stool will depend on how much water is reabsorbed while passing through the large intestine. The shorter the transit time, the less water is reabsorbed from the faeces, resulting in a softer stool.
Very soft or ‘sticky’ stools (best described as having a toothpaste or peanut butter consistency) are difficult for muscles along the digestive tract to push through effectively and can be hard to completely empty from the rectum. The pooling of soft stools within the bowel can also lead to constipation over time.
Bristol Stool Chart
| TYPE | DESCRIPTION | IMAGE |
|---|---|---|
| Type 1 | Separate hard lumps, like nuts (hard to pass) |  |
| Type 2 | Sausage-shaped but lumpy |  |
| Type 3 | Like a sausage but with cracks on its surface |  |
| Type 4 | Like a sausage or snake, smooth and soft |  |
| Type 5 | Soft blobs with clear-cut edges (passed easily) |  |
| Type 6 | Fluffy pieces with ragged edges, a mushy stool |  |
| Type 7 | Diarrhoea may have undigested food particles Liquid only can be overflow = constipation |  |
Reference: Heaton, K W & Lewis, S J 1997, ‘Stool form scale as a useful guide to intestinal transit time’. Scandinavian Journal of Gastroenterology, vol.32, no.9, pp.920 – 924.
For upper motor neurone bowel
Aim for stool consistency (type 2-4 on the Bristol Stool Scale) that is easier to remove fully and is less likely to result in constipation.
For lower motor neurone/cauda equina syndrome
Aim for a stool consistency (type 2-3 on the Bristol Stool Scale) that is firmer, less likely to leak out and easier to completely remove, with reduced risk of an unplanned bowel movement later in the day.
LMN bowels have relaxed anal and rectal muscles, with active abdominal muscles.
What influences consistency?
The consistency of the stool can be influenced by substances that can draw water into the bowel. In this situation, the risk of constipation increases and fluid intake should be encouraged to the highest volume a person can manage.
Fluids
Getting the right consistency can often be achieved simply by drinking enough fluid.
The recommendation is for 2-3 litres of fluid a day, mostly water. This may be difficult to achieve for those trying to prevent bladder leakage or who are self-catheterising. Be mindful that both of these circumstances can increase the risk of constipation.
Softeners
‘Softeners’ work by retaining or drawing water back into the faeces. They work best when taken a few times during the day. Dietary ‘softeners’ can be fruit (especially apples, pears, stone fruit, watermelon or any dried fruit including prunes) and juices high in sorbitol (such as pear juice, apricot nectar, kiwi fruit juice or prune juice).
Common medications that can soften the stool are:
- Docusate (eg. Coloxyl)
- Macrogol (eg. Movicol/Clearlax/Osmolax)
- Sorbitol
- Liquid Paraffin (eg. Agarol, Parachoc)
- Lactulose
- Epsom salts.
Firmers
The most common dietary firmers are those high in soluble fibre, including oats, legumes, bananas, vegetables (such as sweet potato, carrot, green beans, potato, Brussel sprouts), nuts and seeds, such as chia seeds and flaxseeds. For some people, a fibre supplement may be needed to firm the stool.
Some examples are:
- Psyllium husk (e.g. Metamucil)
- Wheat dextrin (e.g. wheat bran or Benefibre)
A good starting dose is ½ teaspoon twice a day, increasing every few days as needed. See the Right amount for more information on different types of fibre.
A high-fibre diet and/or taking a fibre supplement without adequate fluid can lead to the fibre ‘setting like concrete’ in the bowel, and increasing the risk of constipation.
There should also be a gap between taking fibre supplements and taking medications. As fibre can impair the absorption of some medications, it is recommended that fibre supplements and medications be taken at least two hours apart.
When making any changes to diet or medication, to improve bowel habits, note that it may take at least 2-3 days to start seeing the effect. This is especially relevant for softening and firming agents. Make small changes, wait a few days, reassess and progress with further changes if needed.
Stimulants
These were discussed previously in the Right Place. It is important to remember that changes to diet or stimulatory medications can directly influence the consistency of the stool.