What Is IBS
IBS is a disorder of the gut-brain interaction that impacts the digestive system. It’s a chronic condition that causes significant bowel discomfort and influences bathroom habits. Depending on the type of IBS you have, you may experience constipation, diarrhea, or both.
What Causes IBS
More research is necessary to fully understand why IBS happens, but there are multiple factors that may contribute to this condition.
Gut Microbiome Imbalance
Your gut is home to all sorts of microorganisms that assist with digestion. There’s a delicate balance that can cause issues if it’s thrown off. The specific organisms that are off balance vary with each type of IBS, but all three types are linked to increased Escherichia/Shigella (Su et al., 2023).
Stress
The amount of stress you’re experiencing influences every aspect of your health. Increased stress is linked to IBS and may spark the onset of new symptoms or a flare up in existing IBS (Nathani et al., 2025).
Food Intolerance
Sensitivities or intolerance of certain foods can also influence IBS. Up to 65% of people with IBS report having food intolerance, but the overwhelming consensus is that this can’t cause IBS alone. Instead, it’s more likely that food intolerance and sensitivities can aggravate symptoms (Nathani et al., 2025).
Disordered Gut-Brain Axis
Your brain-gut axis is the communication between your brain and gut. Through this link, the emotional and cognitive centers of your brain are directly connected to your gut. As a result, the brain influences gut health and vice versa (Carabotti et al., 2015). This communication happens via neuronal, endocrine, immune, and metabolic pathways.
The things you eat, your genes, the amount of stress you experience, and many other factors can influence these lines of communication. When that happens, it can trigger IBS (Nathani et al., 2025).
Postinfection Immune Activation
Having an acute illness can put you at increased risk for IBS. A lot of the time, this is limited to stomach bugs caused by bacteria, viruses, and other microorganisms. But research is showing that COVID-19, which is often thought of as a respiratory illness, may also cause postinfection IBS (Ghoshal, 2022).
Who Is at Risk
Anyone can experience IBS, but there are some factors that may increase your risk. In addition to genetics, recent infection, and food intolerances and sensitivities, there are several other things that can increase your risk for this gastrointestinal condition.
The things you eat matter. Having a diet high in ultra processed and fatty foods can throw your gut microbiome off kilter and spark the onset of IBS. Consuming a significant amount of alcohol can also be a factor.
Environmental factors are also linked to IBS. Exposure to cigarette smoke, air pollution, and poor sanitation are associated with IBS, as well as pet ownership.
IBS is also comorbid with a wide variety of other health conditions, from mental health concerns like anxiety and depression to chronic health conditions like diabetes and asthma (Sulaimi et al., 2025).
What Are the Symptoms
No matter what type of IBS you have, the main complaint is gastrointestinal discomfort. But that discomfort is caused by different things depending on the type of IBS you have.
IBS-C
IBS with predominant constipation (IBS-C) causes at least a fourth of your bowel movements to be constipated. On the Bristol Stool Form Scale, these bowel movements look like types 1 and 2. If you have this type of IBS, less than a fourth of your bowel movements are diarrhea, or types 6 or 7.
Stomach pains from this type of IBS are from your gut being backed up and gas from bloating.
IBS-D
IBS with predominant diarrhea (IBS-D) makes at least a fourth of your bowel movements diarrhea and less than a fourth constipated. This type of IBS can cause sharp abdominal pains and sudden urges as stool travels through your colon.
IBS-M
IBS with mixed bowel habits is a combination of the two. More than a fourth of your bowel movements are constipated and more than a fourth are diarrhea.
IBS-U
If you’re experiencing IBS symptoms but you don’t fully align with the other three types, you may have IBS unclassified (IBS-U). This category is reserved for anyone who has the symptoms of IBS, has ruled out other diseases, and doesn’t fit neatly into the criteria for IBS-C, -D, or -M.
How Is IBS Diagnosed
Getting a diagnosis for IBS can be a little tricky. Best practice for healthcare providers is to rule out other, more serious conditions. You may be tested for food allergies, your healthcare provider may collect stool samples, give you a digital rectal exam, and you might need blood drawn for different labs. And keeping a diary to keep track of your diet and bowel habits is really helpful for this process.
Your healthcare provider will most likely order a colonoscopy. This screening tool will allow them to rule out colon cancer and many other conditions, including Crohn’s disease and diverticulosis. If all is well with your colonoscopy and there aren’t any other concerns, your healthcare provider will likely diagnose you with IBS.
How Is IBS Treated With Regenerative Therapies
There are so many treatment options for IBS. However, many of them only help manage symptoms since so little is understood about this condition.
Fecal Microbiota Transplantation
While there needs to be further research to fully understand the benefits of fecal microbiota transplantation (FMT), there’s evidence to suggest that it’s helpful for treating IBS. FMT is a procedure where a healthcare provider collects feces from a healthy donor to transplant it into a recipient with IBS or another relevant gut condition. The feces is then delivered to the gut of the recipient through an enema, colonoscopy, nasogastric tube, or even through oral capsules.
There’s evidence showing that FMT is effective for improving IBS symptoms and the risk for adverse events is low. It’s also inexpensive and easy to perform (Wu et al., 2024).
Probiotics
Your gut is filled with good bacteria that helps you break down food for digestion. This collection of microorganisms is called your gut microbiome. To support a healthy microbiome, many people consume probiotics. Probiotics are live microorganisms, like bacteria and yeast, that help promote the healthy microorganisms in your gut.
For people with IBS who may be experiencing an imbalance in their gut microbiome, probiotics can help. Studies show that Bifidobacterium and Lactobacillus are two effective probiotics for treating IBS. However, Bacillus coagulans seems to be the most effective given the information that is currently available. More studies are needed to clarify which probiotics are most effective for each type of IBS (Wu et al., 2024).
Gut-Directed Hypnosis
If you have IBS, you’re likely familiar with abdominal cramping and issues with gut motility. Gut-Directed Hypnosis helps address these symptoms by intervening in the miscommunication that occurs between your brain and gut. It does this through imagery, relaxation, and suggestion. And research shows that’s an effective treatment option.
Over three-fourths of people with IBS respond to gut-directed hypnotherapy. Studies show that the improvements these patients experienced endured long term (Häuser, 2024).
Psychotherapy
There is a wealth of data on the efficacy of psychotherapy in treating IBS. Self-administered or minimal contact CBT, face-to-face CBT, and gut-directed hypnotherapy have been tested more than other modalities, but there is evidence that other types of therapy are also effective. Studies show that psychotherapy is more effective in IBS management than education and support alone (Black et al., 2020).
Diet Changes
One of the first lines of treatment for IBS is making dietary and lifestyle changes. Your healthcare provider may suggest a low-FODMAP, gluten free, and/or high fiber diet depending on what you typically eat. You’ll also need to avoid any foods that you have sensitivity or intolerance for.
A low-FODMAP diet usually eliminates dairy, limits caffeine and alcohol, and avoids foods like beans that produce lots of gas. After 4-6 weeks, you’ll slowly start reintroducing eliminated foods back into your diet. This way, you can more easily identify foods that trigger your IBS symptoms and avoid them in the future.
Lifestyle Changes
Your daily habits have a significant impact on your gut health. Getting active can help manage IBS symptoms. This may help by improving the motility in your gut. Good sleep hygiene is also associated with improving IBS symptoms.
Medication
If other treatment options aren’t helping or your symptoms are causing severe disruption in your daily life, there are medications that can help. If you have IBS-C, your healthcare provider may prescribe medication to help get your gut moving. This may include a laxative or other medications that literally make your bowels move.
For IBS-D, your healthcare provider may prescribe medication to prevent diarrhea or an antibiotic called rifaximin. There are also other medications your healthcare provider may suggest to treat your symptoms, including medications to prevent stomach cramps and treat depression—especially if antidiarrheal drugs and rifaximin don’t work (Nathani et al., 2025).
Taking peppermint oil can help, too. Research shows that peppermint oil may help relax your bowels to help reduce pain from cramping associated with IBS.
What Are Possible Complications
Complications from IBS are limited to the mental health impact it has and physical complications like fecal impaction, hemorrhoids, anal fissures. Pain associated with IBS may have ripple effects, like interfering with work, school and social activities as well.
Can IBS Be Prevented
While IBS itself can’t be prevented altogether, there are several steps you can take to reduce your risk for both onset and flare ups. Manage stress in your daily life, avoid taking antibiotics unnecessarily, and avoid foods that upset your stomach. You can also stay active and prioritize healthy sleep habits to help prevent IBS.
Takeaway
IBS is an uncomfortable condition caused by disrupting the brain-gut axis. There are four different types: IBS-C, IBS-D, IBS-M, and IBS-U. IBS-C is characterized by constipation while IBS-D causes diarrhea. IBS-M is a combination of IBS-C and IBS-D symptoms, and IBS-U describes cases that don’t match the criteria for the other three types.
Getting a diagnosis for IBS is based on ruling other, more serious bowel diseases out. A colonoscopy is the golden standard for ensuring IBS symptoms aren’t the result of colon cancer or any of a number of inflammatory bowel diseases.
Treatment varies, but lifestyle and dietary changes are the first line options. If that doesn’t provide effective relief, regenerative treatments, psychotherapy, and medication are other effective options.
