IBS and Pregnancy – Dietitian Advice

Many women may feel a sense of concern when thinking about how they will manage their IBS and pregnancy. However, the advice for IBS and pregnancy does not differ hugely to the standard advice given for common symptoms during pregnancy.

This article will clarify the main questions about IBS and pregnancy through the management of various common pregnancy symptoms. These include constipation, morning sickness, haemorrhoids and iron deficiency anaemia.

How does IBS change during pregnancy? 

You will be sad to know that we have no specific research looking at IBS and pregnancy.

What we do know is that in pregnancy, you may experience a range of common digestive issues including;(1)

• Nausea
• Vomiting
• Heartburn
• Constipation
• Loose stools
• Abdominal pain and discomfort.

All of these digestive symptoms are also often experienced in those with IBS. Theoretically, these symptoms may then get worse when you add pregnancy to the mix. But there is currently insufficient research to confirm this. 

Another element we see in practise is stress. For many women, pregnancy and childbirth can be quite daunting. We know that stress can impact IBS negatively via the gut-brain axis (1).

How do pregnancy hormones impact IBS?

As already mentioned, there is no direct research looking at IBS and pregnancy. But we do know that progesterone and oestrogen hormones impact IBS (2).  These hormones fluctuate during pregnancy.

Oestrogen in pregnancy and IBS

Oestrogen is produced early in pregnancy to help support the baby until the placenta takes over.

This hormone oestrogen has been shown to play a role in the gut-brain axis and increased levels have been associated with the worsening of  IBS symptoms. 

Symptoms include:  visceral hypersensitivity i.e. an increase in the sensation of pain resulting in abdominal pain and discomfort (3). 

High levels of oestrogen have also been shown to increase gut motility and intestinal permeability. This can result in diarrhoea or loose stools (3).

Progesterone in pregnancy and IBS

The production of the hormone progesterone is increased during pregnancy which is important for the healthy development of the baby. 

Progesterone along with oestrogen has been shown to produce a prolonged gut transit time resulting in constipation (4).

How to manage constipation when pregnant

Constipation is a very common symptom in both IBS and pregnancy. The good news is that managing constipation with IBS and pregnancy is not any different to managing constipation with pregnancy alone.

Causes of constipation during pregnancy; (5)

• Increased progesterone
• A reduction in movement and physical activity
• Changes to your diet including a lack of fibre or fluid (this can often be due to nausea).
• Taking iron and calcium supplements

Management of constipation in pregnancy

Taking the following steps can help manage your constipation when pregnant with IBS.

1. Drinking adequate amounts of fluid
2. Eating a high fibre diet
3. Moving daily (please check what is appropriate with your doctor).
4. fibre, fluid and daily movement can help to prevent or alleviate constipation with IBS and pregnancy. 

We have written this more comprehensive guide on constipation which you may wish to read.

TIP: Keeping a food log to see what foods trigger your IBS symptoms during pregnancy can also be helpful to know which ones to avoid!

Medications for constipation for IBS and pregnancy 

There are many over the counter constipation medications available. BUT rarely have they been researched for safety in pregnancy. So, be safe and consult with your doctor first.

How to manage morning sickness

Nausea and vomiting are not symptoms of IBS but commonly occur in the first trimester of pregnancy (6).

As with anyone who is pregnant and experiencing morning sickness, the symptoms should ease throughout your pregnancy. If you are really struggling, there are some dietary and lifestyle changes that could help to ease your symptoms. 

Dietary and Lifestyle changes for morning sickness (7)

• Get plenty of rest as tiredness can make nausea worse
• Avoid the foods or smells that make you feel sick
• Eat dry toast or a plain biscuit before getting out of bed
• Eat small, frequent meals of plain foods that are high in carbohydrate and low in fat and IBS appropriate for example, wheat free bread, crackers etc.
• Eating cold foods instead of hot ones if the smell of hot meals makes you feel sick.
• Stay hydrated – sipping little and often to help prevent vomiting
• Eating and drinking little and often which can also help to prevent dehydration

If you are suffering from severe and frequent vomiting and feeling dehydrated, please seek prompt medical advice. 

How to manage haemorrhoids when pregnant

Haemorrhoids, also known as ‘piles’ can occur in pregnancy due to hormones making your veins relax. Typical symptoms include itching, aching, soreness or swelling around the anus (8).

Below are the various ways of dietary, lifestyle and pharmacological management tools for haemorrhoids when pregnant. 

Dietary and Lifestyle Management (9)

• Avoid constipation (see section above)
• Avoid standing for long periods
• Engage in regular movement and exercise (based on what your doctor has advised is safe).

Pharmacological management (9)

Certain medications can help to soothe and alleviate the inflammation caused by haemorrhoids but they do not treat the cause of haemorrhoids. 

Ask your GP or pharmacist for advice on suitable medications for haemorrhoids with pregnancy and IBS.

How to manage iron deficiency when pregnant 

Iron deficiency can occur in pregnancy due to poor dietary intake and increased requirements.

If you become deficient in iron then your doctor will prescribe a supplement. Sadly, these usually cause digestive problems such as nausea, flatulence, abdominal pain, diarrhoea black/tar-like stools and in particular constipation! (9)(10).

To alleviate the symptoms related to iron supplements, try to follow our advice on constipation above.

Prevention of iron deficiency in pregnancy (11, 12)

High dose iron supplements required to treat anaemia can cause constipation. So, it is important to avoid anaemia by including iron sources in your diet.

Below are some haem and non-haem iron rich foods that you incorporate into your  diet;

• Haem iron include red meat, pulses, dried fruits and fortified foods such as breakfast cereals. Animal sources of iron including red meat tend to be a more highly absorbable form of iron known as haem iron. 
• Non-haem iron – Plant foods including green leafy vegetables, legumes and beans tend to be a less absorbable form of iron known as non-haem iron. This is why combining vitamin C with non-haem sources of iron from plants can help boost its absorption. For example, a glass of fruit juice with a meal. Also, consuming higher quantities of plant sources of non-haem iron can also help to boost its absorption. 
• Phytates and oxalates are compounds found in tea and calcium rich foods including dairy which can impact the absorption of iron. This is why it is best to avoid these foods and drinks with iron-rich meals. For example, drinking milk with meals.

Can you do the low FODMAP diet whilst pregnant?

The simple answer is no. This is due to the restrictive nature of the diet, meaning that you may restrict nutritional deficiencies. This could potentially impact your baby.

Summary

Overall, many of the common digestive symptoms experienced throughout your pregnancy are also experienced with IBS. This could explain why symptoms of IBS in pregnancy can appear worse. 

Although there is a limited amount of evidence around the management of IBS and pregnancy, with support from a registered dietitian and your doctor, there are a range of dietary, lifestyle and in some cases pharmacological approaches to help alleviate these digestive symptoms.

Emily Stynes BSc. in Human Nutrition and reviewed by Kirsten Jackson

Last updated on October 25th, 2021 at 08:37 am