Types of MS bowel problems

MS can stop your bowels emptying as often as they normally do. This is constipation. 

Or you can have a problem holding poo in. This is bowel (faecal) incontinence (leakage of poo that you can’t control). 

For some people these problems overlap and happen at the same time. Watery poo builds up behind a mass of hard poo, then leaks from around it.    

What causes MS bowel problems? 

Bowel problems happen when MS causes nerve damage that stops your bowel working like it should 

Your bowel is a long tube made of muscle. Nerves in it make it squeeze to push poo forward. They also let you feel when your rectum is full.    

Nerves in your two anal sphincters make them open and close to let poo out.   

Nerves also make muscles around your bowels, like your pelvic floor muscles, help you push poo out.   

All these nerves send signals from your bowel, up your spinal cord and onto parts of your brain that control pooing (and back again).

MS nerve damage can:   

• affect the many ways that muscles make your bowels work    
• stop you being so physically active. This will make your bowels sluggish   
• slow you down. That can stop you reaching the toilet fast enough    

For some people a bowel problem (often constipation) was an early sign that they had MS. For others bowel problems begin later.

The nerves that control your bowels and legs are at the base of your spine. That’s why walking and bowel problems can go hand in hand. Areas of nerve damage (MS lesions) on this part of your spinal cord can cause both symptoms. 

Constipation: when your bowels don’t empty often enough

With constipation there’s a change in how often you poo compared to your usual bowel pattern. Between three times a day to three times a week is normal when you're not constipated. But with constipation you either don’t poo often enough. Or it’s difficult to poo at all.  

MS might damage nerves which can cause your bowels to slow down. This means too much water gets absorbed from it. That makes it less soft and so it’s harder to poo.     

You’re probably constipated if you’ve had some of these symptoms for three months:    

• you poo less than three times a week    
• you spend a long time trying to poo, but nothing happens    
• hard, dry, lumpy poo (types 1-2 on the Bristol Stool Chart). When poo won’t move through your bowels, it’s called ‘impaction’    
• you strain when you’re on the toilet    
• you feel sick or bloated (or it hurts to poo)    
• you feel you’ve not fully emptied your bowels    
• you don’t feel hungry (and lose weight)    
• watery diarrhoea-like fluid (this can leak from behind hard, impacted poo)    
• you can’t tell if your rectum (back passage) is full (while having the symptoms above)

See the Bristol Stool Chart at the Bladder and Bowel Organisation website   

Bowel incontinence: when you leak poo   

Bowel incontinence describes when you can’t control when your bowels empty. This leads to you leaking poo.   

Incontinence isn’t as common as constipation. About half of people with MS might get this sort of leakage. But a bowel accident in public can be very upsetting. When you’re out, you can get anxious about where the nearest toilet is. You might avoid leaving the house in case you have a bowel 'accident'. We look at solutions to these problems later.  

Nerve damage caused by MS can cause leakage by: 

• weakening nerves in your anal sphincters that hold poo in 
• making you no longer feel you need to poo. So poo leaks out, or you get a sudden need to urgently poo    
• stopping you being able to hold in as much poo as you once could.  
• making poo travel through your bowel too fast, so that it’s runny. That makes it harder to feel that your rectum is full   

These are symptoms of bowel incontinence:    

• you leak poo. And you may also not be able to control when you pass wind     
• you might not even notice the leakage until after it’s happened     
• you notice stains or poo on things you’re wearing    
• you have a sudden need for the toilet, then have an accident because you can’t get to it soon enough 

Find out about managing bowel problems