Current treatment options for IBS with diarrhea


Diarrhea, loose stool, the runs, or holiday tummy. Whatever you call it, diarrhea is probably something we have all experienced at some point in life. Prolonged diarrhea can have a major impact on life and IBS with diarrhea (IBS-D) is one of the most common IBS subtypes worldwide. So what are the current treatment options for IBS-D?

What is diarrhea?

Our gastrointestinal tract is tasked with digesting food and providing the body with nutrients and water. Muscle contractions transport food through the gastrointestinal tract (motility) and the body releases various substances in the gastrointestinal tract that help break down and transport the food further through the intestines (secretion). Nutrients and fluid are transported through the intestinal wall into the body (absorption).

Diarrhea occurs when there is an imbalance in these systems, leading to more than three loose stools per day. The rapid passage through the intestines during diarrhea means that the stool contains up to 90 percent water and undigested food. Diarrhea can be acute or chronic (more than four weeks). It is also considered chronic if it comes and goes periodically. Prolonged diarrhea can cause fluid and nutrient deficiencies and disturbances in the salt balance.

What causes the imbalance?

The imbalance can be caused, for example, by infections, inflammation, problems with absorbing nutrients (so-called malabsorption), tumors, or disorders of intestinal motility. Underlying factors can be viruses or bacteria, but also diet (for example gluten intolerance and lactose intolerance), alcohol, drugs, surgeries, and many different diseases (for example IBS, IBD – inflammatory bowel disease, pancreas, appendicitis). Even stress and anxiety can cause diarrhea.

What are the symptoms of diarrhea?

  • Loose stools. In order to be able to distinguish different stool consistencies, a scale called the Bristol Stool Form Scale has been developed that can be used to determine the consistency of the stool.
  • Fever, blood, and mucus in the stool. In addition to the loose stools, other symptoms such as fever, blood, or mucus in the stools may appear.

Diarrhea and IBS

IBS (Irritable Bowel Syndrome) is mainly characterised by other symptoms such as recurrent pain or discomfort in the abdomen. Therefore, in order for diarrhea to be part of an IBS diagnosis, it should occur at the same time as the pain/discomfort is relieved after toilet visits.

Current treatment options

Typically, non-pharmacological therapies are preferred in those with mild severity, however, changes in certain lifestyle habits should be implemented even with pharmacological therapy for those with more severe symptoms.

IBS-D treatment options

Healthy diet

It is recommended to limit alcohol intake, reduce the intake of processed and fatty foods, and limit sugar intake. Since you lose a lot of water when you have diarrhea, it is important to get fluids, especially if you have a fever. Gluten or lactose intolerance is also more common in IBS patients. That is why avoiding dairy or going gluten-free can relieve symptoms for some people. The most popular diet recommended is the low-FODMAP diet. FODMAPs are a group of poorly absorbed carbohydrates that are fermented by intestinal bacteria. This leads to water being drawn into the lumen and to an increase in gas.

The effectiveness of these diets depends on what’s triggering your IBS. What works for one person does not necessarily need to work for another. Altering the diet is definitely recommended but it’s better to do it under the supervision of a trained dietician, so you are not missing out on important dietary nutrients.


Probiotics (‘good’ gut bacteria) are often used to improve healthy balance in the gut microbiome. They have been found to be effective in relieving symptoms for some people. Learn more about probiotics and how they work.

Regular exercise

There is no doubt that regular physical activity is important for both physical and mental well-being. Studies show moderate-to-vigorous physical activity (20-60 minutes, 3 to 5 days per week) is effective in relieving IBS symptoms. Learn more about training with IBS.


We now know that the brain is connected to the gut through the gut-brain axis. That explains why mental health disorders or even stress can lead to the worsening of IBS symptoms. IBS patients generally benefit from evidence-based psychological approaches. They help to manage stress response and potentially decrease inflammation. More research needs to be done to understand how the therapies work and how to make them more targeted in IBS-D patients.

As for symptomatic treatment, there are over-the-counter drugs for diarrhea with loperamide (Dimor, Loperamide, Imodium, Primodium).


Nee, J., & Lembo, A. (2021). Review Article: Current and future treatment approaches for IBS with diarrhoea (IBS‐D) and IBS mixed pattern (IBS‐M). Alimentary Pharmacology & Therapeutics54(S1).