What Are the Different Types of IBS?

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Irritable bowel syndrome (IBS) is a gastrointestinal (GI) disorder that can cause abdominal pain and changes in bowel habits. The exact symptoms you experience may vary based on your type of IBS.

Knowing your exact type of IBS is important for determining the correct treatment. This article will describe the different types of IBS and their symptoms, as well as causes and treatment options for IBS.

Irritable Bowel Syndrome (IBS)

Types of IBS

IBS type is generally based on the primary symptoms you are experiencing relating to changes in bowel movements. Some days your bowel movements may be normal, while other days, they are not. Symptom severity can range from mild to severe.

Paying attention to your bowel movements and how often they occur can help you and your healthcare provider identify which type of IBS you have.

IBS-C

With IBS with constipation (IBS-C) subtype, on days when you are experiencing abnormal bowel movements: 

  • More than one-fourth of your stools are hard or lumpy, and 
  • Less than one-fourth of your stools are loose or watery

IBS-D

With IBS with diarrhea (IBS-D) subtype, on days when you are experiencing abnormal bowel movements: 

  • More than one-fourth of your stools are loose or watery, and 
  • Less than one-fourth of your stools are hard or lumpy

IBS-M or IBS-A

With IBS with mixed bowel habits (IBS-M) or IBS with alternating bowel habits (IBS-A) subtype, on days when you are experiencing abnormal bowel movements: 

  • More than one-fourth of your stools are loose or watery, and 
  • More than one-fourth of your stools are hard or lumpy

Post-Infectious IBS

Post-infectious IBS (PI-IBS) occurs after experiencing an infection in the GI tract, such as food poisoning. Even though the infection has resolved, symptoms of IBS continue. Unlike previously described subtypes of IBS, PI-IBS may resolve on its own, though it can take months or years.

Post-Diverticulitis IBS

Post-diverticulitis IBS (PDV-IBS) is similar to PI-IBS in that it occurs after another GI-related condition. PDV-IBS happens after a flare of diverticulitis (inflammation of pouches that can form along your intestinal tract), causing prolonged GI symptoms even after the diverticulitis flare has improved.

How Does IBS Affect the Body?

Researchers are still looking into the ways IBS impacts the body. Upon investigation, people with IBS have GI tracts that appear normal. Though they may have some overlapping symptoms, this is different from inflammatory bowel disease (IBD), where the GI tract is visibly inflamed and has changed upon investigation.

However, experts suggest that IBS does appear to affect the body in certain ways, which may be related to the symptoms experienced by people with IBS. These include:

  • Abnormal gut motility (movement of food through the GI tract)
  • Over- or underactive immune system
  • Changes in gut bacteria
  • Central nervous system’s misinterpretation of pain signals coming from the gut
  • Minor increase in gut inflammation

IBS Symptoms: All Types

IBS symptoms can vary from person to person and change over time. Symptoms often come and go. People who menstruate may experience more symptoms during their periods.

Aside from diarrhea and constipation, below are symptoms of IBS, regardless of subtype:

With all subtypes of IBS, the Rome IV diagnostic criteria states that people with IBS have had abdominal pain at least one day a week for the past three months that started at least six months ago and is related to at least two of the three below:

  • Defecation (emptying your bowels)
  • Changes in stool appearance
  • Changes in stool frequency

What Are the Causes of IBS?

IBS is a functional GI disorder in which there are problems with how the brain and gut communicate and work together.

The gut-brain axis is two-way communication between the enteric nervous system (in the gut) and the central nervous system (brain and spinal cord). This links the brain and the gut microbiome (a wide variety of bacteria, viruses, fungi, and other microorganisms). 

When this signaling pathway is disrupted, such as with IBS, the gut is more sensitive. This can lead to symptoms such as abdominal pain and bloating. The muscles in your gut may also be affected, causing food to move more quickly or slowly than normal, leading to diarrhea or constipation.

Experts aren’t sure of the exact cause of IBS, though they suspect a combination of factors may lead to the development of IBS. These risk factors include:

How Are Various Types of IBS Treated?

Treatment for IBS depends on the predominant symptoms you are experiencing. Work with your healthcare provider to find a treatment plan for you. You may need to try several treatments to find what works best.

Medications and Supplements

Medication treatment options for IBS may include:

Dietary supplement treatment options may include:

Diet

Because the movement of food through your GI tract is a central aspect of IBS and its symptoms, it makes sense that modifying your diet may help decrease symptoms. To help guide you in identifying your diet triggers for IBS, your healthcare provider may refer you to a registered dietitian nutritionist.

Diet modification recommendations may include:

Activity 

Participating in regular physical activity may help with IBS symptoms and increase quality of life.

In particular, yoga may be helpful. Studies suggest it may reduce stress, anxiety, and depression and improve sleep.

Nevertheless, finding a form of physical activity you enjoy is important, as you are more likely to stick to it—and thus reap the benefits. Walking, jogging, riding a bike, swimming, bodyweight exercises, or participating in a sport such as pickleball, basketball, volleyball, or tennis are all great options.

Holistic Remedies

IBS treatment isn’t just about medications, supplements, and diet. Because of the link between IBS and the gut-brain axis, it’s important to address treatment holistically. Additional treatment options, including for mental health, may include:

Managing Underlying Conditions

People with IBS are more likely to experience a comorbid condition (having two or more conditions at the same time), with an estimated 50% having at least one comorbid condition. In addition, the more overlapping conditions you have may increase the severity of your IBS symptoms. 

Conditions that often overlap with IBS include:

Previously, IBS was thought to be a diagnosis of exclusion, meaning that it is often diagnosed after other diagnoses have been excluded.

Most experts today agree that IBS can be accurately diagnosed based on symptoms, physical exam, and a health history. However, many healthcare providers still believe it’s important to rule out other health conditions before officially diagnosing IBS.

Screening for overlapping conditions and ruling out other potential causes for your symptoms can help narrow treatment options to find the best way to minimize or resolve symptoms. 

Can You Switch From One Type to Another?

There is debate as to which subtype of IBS is most prevalent. Some studies suggest IBS-M is the most common. Other experts state there is equal prevalence among all types of IBS. Regardless of which type may or may not be more common, one thing many experts agree on is that you can switch from one subtype of IBS to another over time.

This is different from IBS-M or IBS-A, where you alternate between constipation and diarrhea on a regular basis, such as daily or weekly. Instead, you experience one type of IBS predominately for months or years, then switch to another type for another prolonged period.

Summary

Irritable bowel syndrome (IBS) is a gastrointestinal (GI) disorder that causes abdominal pain and changes in bowel movements, including diarrhea and/or constipation.

The three main types of IBS include IBS with constipation (IBS-C), IBS with diarrhea (IBS-D), and IBS with mixed or alternating bowel habits (IBS-M or IBS-A). In addition, IBS may develop after experiencing a GI infection (post-infectious IBS) or having a diverticulitis flare (post-diverticulitis IBS).

Regardless of subtype, additional symptoms of IBS include bloating, gas, mucus in the stool, and feeling of incomplete bowel movements. Symptoms can change over time in severity and frequency. It’s also possible to switch subtypes of IBS over time.

IBS symptoms are thought to result from communication problems between the gut and the brain (called the gut-brain axis), resulting in a sensitive gut. Potential reasons for this disruption include genetics, GI bacterial infections, SIBO, stressful or difficult early life events, certain mental health disorders, or food intolerances or sensitivities. 

Treatment options vary depending on your primary symptoms but may include medication, dietary supplements, diet modifications, lifestyle habit changes, and/or holistic treatments, including certain types of mental health therapy.

Managing overlapping health conditions is important to help control overall symptoms and increase quality of life. Working closely with a healthcare provider will help you find the treatment plan.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Brittany Poulson, MDA, RDN, CD, CDCES
Brittany Poulson, MDA, RDN, CDCES, is a registered dietitian and certified diabetes care and education specialist.