Bowel issues in NMO

Bowel symptoms are often difficult and embarrassing to discuss and many people may be reluctant to seek help and advice


Constipation is the passing of hard stools with excessive effort less frequently than three times a week. It can be accompanied by abdominal bloating and discomfort, tiredness and fatigue, and a loss of appetite. There are a number of possible causes of constipation in NMOSD.

• In some people with NMOSD waste matter moves more slowly through the colon. As one of the functions of the colon is to reabsorb water, the longer the transit time, the harder and smaller stools can become. A simple test to indicate transit time is to eat sweetcorn, which is visible in stools. Normal transit time is less than 72 hours.

• Reduced sensation can cause reduced awareness of needing to empty the bowel, exacerbating constipation and, if left untreated, causing overflow incontinence.

• Weakness or un-coordination of the anal sphincters, weakness of the pelvic floor muscles, and anatomical problems in the rectum (which can be caused by excessive straining on the toilet, childbirth or heavy lifting) can also cause difficulties.

• If fluid intake is reduced in an attempt to manage bladder symptoms, the body will compensate by reabsorbing water from stools in the colon and rectum.

• Reduced mobility or lack of exercise can worsen constipation and could also impair someone’s ability to get to the toilet when they need to. Similarly, the timing of carer visits to fit in with a person’s bowel habit can be tricky.

• Eating breakfast initiates a reflex reaction triggering the urge to go to the toilet. However, many people skip breakfast or eat just as they are about to leave home.

• Common medications used in MS can cause constipation as a side effect, including drugs for bladder symptoms, spasticity and depression, as well as iron supplements and antacids. The effect can be multiplied by multiple medications.

• Women can experience changes in bowel pattern due to hormonal fluctuations in menstruation or pregnancy.

Management of constipation

Dietary fibre is required to maintain the bulk and softness of stools. The recommended five portions of fruit or vegetables a day can help with this. Fibre can be increased by adding a tablespoon of linseeds or flaxseeds into the diet, and many people find prune juice or aloe vera juice is effective. However for people with slow transit time, too much fibre can worsen their symptoms and a high fibre diet requires an adequate fluid intake.

Defecation dynamics

The natural posture for opening the bowels is the squat, however this is no longer the position we adopt. Sitting with both feet on a step (like one toddlers use to reach the toilet), with knees slightly higher than hips can help, as can brace and bulging the abdomen to increase abdominal pressure.

It is important to allow enough time. The optimum time is twenty minutes after a meal. If nothing has happened after ten to twenty minutes, try again after the next meal.


Laxatives should really be taken on the advice of a medical professional. Many of the common over the counter preparations are licensed for short-term use and if taken long-term can affect the bowel permanently.

• Bulk forming laxatives (eg ispaghula husk (Fybogel)) can be used if dietary fibre cannot be increased sufficiently. These are not effective in treating acute constipation.

• Osmotic laxatives (eg lactulose or macrogols (Movicol)) work by drawing fluid from the body or by retaining the fluid in the bowel. These require good fluid intake.

• Stimulant laxatives (eg senna or bisacodyl (Dulcolax)) stimulate the colonic nerves. These are usually taken at bedtime to produce an effect the following morning and are recommended for short-term use only. Abdominal cramping is a common side effect.

• Suppositories or mini enemas cause a contraction in the rectum, softening the stool, and causing contraction in the bowel higher up. They can encourage a regular bowel habit if always used at the same time of day.

Anal irrigation

People with NMOSD may benefit from an anal irrigation system called Peristeen. This uses a catheter to insert warm tap water into the rectum, stimulating the bowel to open.


Faecal incontinence

Faecal incontinence is the lack of control over passing stools. The most common cause can in fact be constipation. When a hard plug of impacted stool builds up in the rectum, a loose, watery, diarrhoea like fluid can be passed around it. Incontinence can also be caused by limited sensation, poor anal sphincter tone, over use of laxatives, too much dietary fibre, and gastrointestinal infections causing diarrhoea.

Management of faecal incontinence


If the sphincter muscles around the anus are weak, continence specialist nurses can teach specific exercises that can help people to have more control.


If constipation with overflow has been ruled out as a cause, loperamide (Imodium) or ispaghula husk (Fybogel) can be used.

Containment products

• Disposable pads can be obtained in many areas via local continence/ bladder and bowel services if faecal incontinence is a permanent problem.

• Anal plugs are easily inserted and removed and can used for up to 12 hours. However these should not be used without an assessment by a continence specialist nurse or appropriate healthcare professional.


Skin care

It is important to make sure the skin is kept clean and dry. Barrier creams can be used to prevent soreness, or sprays can be used if skin is already broken and sore.

Quick access

A RADAR key, obtained from or 0207 250 3222, gives access to locked public toilets around the UK. An urgency flash card can be obtained from the Bladder & Bowel Foundation at or 01536 533255.



Effective bowel management involves tailoring a combination of different strategies to each individual. Seek the advice of a relevant professional such as a GP, continence specialist nurse or dietitian. Talking about bowel symptoms might not be as traumatic as you may imagine, and the solution may be straightforward.

If you try any product or idea that helps you in some way please let us know, even if it only reduces the symptoms a little, it may help others too. Please let us know on