PCOS and IBS: Diagnosis, Symptom, and Treatment Overlap

If you’ve been diagnosed with PCOS, your bowel habits should be a topic of discussion with your medical providers. Why? Women with PCOS are at a greater risk of also living with irritable bowel syndrome (IBS). IBS affects 10% of the worldwide population, and 20% of Americans. IBS is a functional bowel disorder that is characterized by changes in the function of the gut (gut motility) and chronic symptoms of abdominal pain, bloating, gas, diarrhea, and/or constipation. These digestive symptoms are also commonly seen in those with PCOS.


Like PCOS, IBS is a disorder that has many potential causes. We still have a lot to learn about IBS, but right now the causes are thought to be either changes to the gut bacterial makeup, or microbiota, or structural changes to the gut. These can be caused by chronic stress (physical and psychological), post traumatic stress disorder (PTSD), chronic antibiotic use, or gastroenteritis. IBS is diagnosed according to Rome criteria, based on changes in gut motility, presented as diarrhea and/or constipation, and chronic symptoms. Symptoms have to occur at least 3 days each month for 3 months or longer. It is common for IBS to present in adulthood, but many of the factors leading to IBS may occur during childhood, when the gut microbiota is developing. IBS is diagnosed according to this criteria once other conditions have been ruled out, including celiac disease and other allergies, Crohn’s disease, ulcerative colitis, and colon cancer. SIBO (small intestinal bowel overgrowth) may also be tested for, and could present alongside IBS. The more we learn about IBS, the more we see a relationship to the brain via the gut-brain axis, which is the communication pathway between the two. We know anxiety, depression, and psychological stress are linked to IBS symptoms, and vice versa. 

The connection to mental health is also seen in PCOS. There is an increased risk of depression and anxiety in those with PCOS, which could be connected to the presence of IBS. We also know that changes to the gut microbiota, referred to as gut dysbiosis, leads to gut permeability, which may be a cause of systemic inflammation in the body. Gut permeability means that the tight junctions in the gut lining that typically protect the body from foreign invaders has been compromised and is not as tight, so organisms, like bacterial endotoxins and luminal contents, are able to pass through the gut lining. The presence of bacterial endotoxins in the blood, called endotoxemia, triggers inflammation. Continued release of bacteria and luminal contents into the bloodstream favors systemic inflammation. Systemic inflammation is linked to insulin resistance, which is a major factor in the cause of PCOS. 

When it comes to treatment for IBS and PCOS, there are many similarities between the two. Both are managed through a holistic nutrition and lifestyle approach, including changes to diet and modifications in stress management, exercise, and sleep. For IBS, the top nutritional approach is the low FODMAP diet. FODMAPs are fermentable (gas-causing) components of carbohydrates that can be difficult to digest for those with IBS, resulting in symptoms. FODMAPs are broken down into the subgroups fructose, mannitol, sorbitol, galacto-oligosaccharides, fructan, and lactose. Not every individual with IBS will be triggered by all FODMAPs. Each person has their own tolerance, most likely due to the makeup of bacteria in their gut. The low FODMAP diet is designed in three phases to help individuals with IBS identify their specific FODMAP triggers. Phase one is elimination, where all FODMAPs are removed from the diet. Phase two is challenge, where FODMAPs are reintroduced by subgroup and symptoms are observed. Phase three is customization, where more FODMAP-containing foods are incorporated back into the diet based on subgroup triggers and tolerance. This is a nutritional approach, so it should be followed under the guidance of a dietitian. In addition to identifying and avoiding trigger foods, it’s also important to focus on a diet that will increase beneficial bacteria, and reduce negative bacteria, in the gut. This is done through a focus on plants, hydration, and adequate intake of fiber, while limiting excessive amounts of sugar, caffeine, and alcohol. Since stress plays a major role in the cause of IBS and symptoms, it’s vital to manage stress through creating boundaries around time, incorporating daily self-care practices, exercise, breath and meditation, and adequate sleep. Those with IBS benefit most from low-intensity exercise, like weight training, yoga, pilates, barre, and light cardio. High-intensity and long duration workouts can lead to IBS symptoms because they increase the release of the stress hormone cortisol, which then triggers symptoms.

There is an overlap in the management of PCOS. For PCOS, the major focus is on hormone balance and the balance of blood sugars to support insulin sensitivity. This can be done through reducing foods that are linked to inflammation in the body, balancing carbohydrates with fiber and healthy fat, and similar lifestyle modifications to those made with IBS that support hormone balance and reduce inflammation. Those with PCOS may already be avoiding foods like gluten, dairy, and sugar, which are also limited for IBS as wheat contains fructans and dairy contains lactose. Exercise, stress management, and sleep recommendations are also the same to balance stress and endocrine hormones. 

If you have both IBS and PCOS, there are a few things to consider. If you’re eating a lower carbohydrate diet to manage PCOS, be mindful to eat an adequate amount of fiber through non-starchy vegetables. Examples of these include greens, bell pepper, broccoli florets, bok choy, and cucumber (these are all low FODMAP options!). If you’re eating a low FODMAP diet for IBS, be aware of how you are balancing out carbohydrates for PCOS. If you are eating meals heavy in starches, like grains and potatoes, it may be helpful to reduce portion sizes to ¼-½ cup, depending on the level of your insulin sensitivity. 

If you are struggling with both PCOS and IBS, it may be confusing where you should begin with your treatment. Since IBS can directly affect PCOS through gut permeability, it may be helpful to work with an IBS-specialist dietitian to identify trigger foods and develop lifestyle habits to reduce IBS symptoms and improve beneficial gut bacteria. Once that has been established, work with a PCOS-specialist dietitian to modify the diet and plan to support your specific type of PCOS. You could also do this in reverse if you have already begun working with a dietitian for PCOS.