Post Infectious IBS – How To Manage

Post infectious IBS is a common type of IBS which typically starts after having some sort of gut infection.

The exact cause of IBS is frustratingly not known in many cases as there is no real clear change in structure or biochemistry that can be measured in IBS sufferers [1]. 

We are now getting to know more about the possible links and potential causes – which is explained in more detail in this post: “What are the Signs and Symptoms and Causes of IBS”.

If you’re wondering if your IBS symptoms have started after a nasty bug or food poisoning, then you could be right, and you could have post-infectious IBS [2]. 

In this article I will explain what post-infectious IBS is and how it can be treated, to help you take the first step in taking control over your symptoms.

What is post infectious IBS?

Post infectious IBS is characterised as new IBS symptoms, as classified by the Rome V criteria, that start following infectious gastroenteritis [3]. 

Infectious gastroenteritis is inflammation of the gut that can lead to vomiting and diarrhoea. It is often caused by bacteria, viruses or parasites, such as food poisoning. This is one of the strongest known risk factors for IBS development [3]. 

You may think back to when your IBS symptoms started and remember having a nasty stomach bug beforehand. This may be responsible for the gut symptoms that you still suffer from now!

What are the symptoms of post infectious IBS?

It may not come as a surprise to you that mixed type symptoms are the most common in post infectious IBS. This means that your symptoms include both constipation and looser stools [4].

The next most common type of symptoms is diarrhoea predominant [4].

What causes symptoms in PI-IBS?

We do not really know exactly how these symptoms come about. We do however know that the following changes may take place in the gut after the infection [2]:

• Low grade inflammation of the lining of the gut
• Increased size of mast cells
• Changes in immune cells of the lining of the gut and/or peripheral circulation
• Changes in the gut microbiome 
• Increased gut permeability 
• Gut motility and visceral hypersensitivity 

These changes can disturb the gut-brain axis, possibly causing your IBS symptoms. 

How common is post-infectious IBS?

The current research into how common post infectious IBS is quite poor and further research is needed. This is tricky to capture and results can be flawed – you may not even recall your episode of gastroenteritis!

One systematic review and meta-analysis found that more than 1in 10 people with infectious gastroenteritis developed IBS later on. Whilst, gastroenteritis increased the risk of developing IBS by more than 4 times [5].

You have more risk of developing post infectious IBS if [4, 6]:

• You are female
• You suffer with anxiety or depression
• Your symptoms during gastroenteritis included abdominal pain, bloody stool and >7 days of diarrhoea
• You had certain types of infections
• Within 12 months of your gastroenteritis episode 
• You took antibiotics to treat your gastroenteritis 

How is post-infectious IBS treated?

There are currently no guidelines or recommendations on the treatment of PI-IBS [3].  This does not mean that there aren’t strategies that may help you in managing your symptoms. 

The strategies to manage post infectious IBS are therefore the same as the management strategies for IBS and should be guided by your symptoms and which type of IBS you fall under. 

For example, if you suffer with symptoms that fall under the IBS-D category, the strategies to reduce the severity of your symptoms will be the same as for IBS-D management [7].

It is important to remember that IBS is multifactorial. This makes it hard to know which management strategy will work for you and being guided by a Dietitian can help you with this process to discover the right method for you.

Your post infectious IBS symptoms can reduce over time and can eventually resolve completely. Some research has shown that less than half of participant’s symptoms resolve within 6 years [6].

Summary

Post infectious IBS is characterised by IBS symptoms following infectious gastroenteritis. Infectious gastroenteritis is one of the strongest risk factors for IBS, increasing your risk by 4 times.

Your symptoms are a result of changes that take place in the gut, such as inflammation and changes in the gut microbiota. This is due to disturbance of your gut-brain axis. 

There is no widely accepted treatment for post infectious IBS and your case is individual. As it is not a one size fits all, there is not always a straightforward answer.

Your management will be guided by the type of IBS symptoms you suffer from. Working closely with a Dietitian can help you discover what strategies are best suited to you and your gut symptoms.

Article written by Beth Wilson (Registered Dietitian with specialist interest in gastroenterology) and reviewed by Kirsten Jackson Consultant IBS Dietitian