Inflammatory Bowel Disease (IBD): Everything You Need to Know

A Closer Look at Crohn’s Disease and Ulcerative Colitis

Medically reviewed by Kumkum S. Patel MD, MPH

Inflammatory bowel disease (IBD) is a group of conditions that cause inflammation in the digestive system. The two most common forms are ulcerative colitis and Crohn’s disease. It’s thought that 1.2 million adults and 58,000 children live with a form of IBD in the United States.

These conditions are called immune-mediated because they’re a result of a problem with the immune system. Genes are associated with IBD, but it is also thought to be triggered by one or more of a number of environmental factors.

This article will discuss inflammatory bowel disease, including causes, symptoms, diagnosis, treatment, complications, management, and living with these conditions.

<p>AleksandarGeorgiev / Getty Images</p>

AleksandarGeorgiev / Getty Images

What Causes IBD?

The exact cause of IBD is not known. However, it’s thought to be a complex combination of a genetic predisposition and environmental triggers. Many genes are connected to the development of IBD. However, not everyone who has the genes goes on to have the condition.

A number of factors are associated with the development of IBD.


IBD can be diagnosed at any age. However, studies show that a diagnosis of ulcerative colitis most commonly occurs in a person's 20s and 30s. Crohn’s disease is diagnosed more often in a person's teens and 20s. Another 16% of people are diagnosed after the age of 65 years. It’s estimated that 4% of people are diagnosed before the age of 5 years.

Genetic Factors

More than 240 genes have been identified as contributing to IBD. About 30 of these genes have a direct connection. IBD does tend to run in families, which has been known for many decades, but not everyone in the family develops the disease.

Race or Ethnicity

People of any ethnic background can develop IBD. However, it does seem to be connected to other factors as well, so that some geographic areas have higher rates of IBD. People of Ashkenazi Jewish descent (people of Jewish heritage mainly descending from Central and Eastern Europe) have a higher risk of developing the disease. White people also tend to be diagnosed with IBD at higher rates than other races.

However, the rate of IBD has also been increasing in industrialized areas of Africa, Asia, and South America.

Environmental Factors

It’s thought that the reason that not everyone who has the genes for IBD gets the disorder is because one or more things trigger it to develop. Some of these are:

  • Air pollution

  • Eating plans that are low in fiber and high in processed foods

  • Disruption in the gut microbiome (the bacteria, viruses, and fungi that naturally live in the digestive system)

  • Infection with a bacteria, virus, or parasite

  • Interactions in the brain-gut pathway that alter the microbiome (such as stressful life events)

  • Living at a higher elevation

  • Smoking, which has a protective effect in ulcerative colitis and exacerbates (worsens) Crohn’s disease

Immune System Dysfunction

IBD is considered an immune-mediated condition. This means that the body’s immune system plays a role in the development of the disease and the flare-ups. The understanding of how this happens is incomplete.

It is thought that the immune system may be targeting the normal bacteria in the gut. Over time, the balance of the gut microbiome is disrupted, which is called dysbiosis. This could be one factor in the development of IBD.


Medications that alter the makeup of bacteria in the gut may also be involved in the development of IBD. Some of these include nonsteroidal anti-inflammatory medications (NSAIDs) and antibiotics. Being exposed to these types of medications often and/or early in life may increase the risk of developing IBD for some people.

IBD Symptoms

IBD tends to affect every person differently. However, there are some signs and symptoms that are more common. There can be symptoms both within and outside the digestive system. Some of the symptoms that IBD can cause include:

How Is IBD Diagnosed?

IBD is most often diagnosed with the use of a colonoscopy with biopsies (removing samples of tissue to be analyzed in a lab). Other tests may be used to give more information about how the condition is affecting the body inside and outside of the digestive system.

Blood tests that might be used include:

Substances in the stool may also be helpful in understanding IBD. Stool tests might be done to look for infection or blood. A test for a protein called calprotectin, which tends to be higher in the stool of people who live with an IBD, may also be done.

Endoscopy procedures are also used in the diagnosis of IBD. A colonoscopy with biopsies is used to see if there is inflammation anywhere in the large intestine. A sigmoidoscopy is used to see the last section of the colon.

An upper endoscopy is used to look at the esophagus, stomach, and first part of the small intestine (duodenum). The biopsy tissue taken during the procedure is sent for testing to look for changes in the cells.

Finding inflammation in the small intestine is more challenging. Imaging tests might be used to look at the organs and structures in the abdomen and see if there is inflammation or other problems. These tests include:

IBD Treatment Options

Treating IBD involves medications, lifestyle changes, and surgery. Every person will have their own treatment plan that is designed for them and how IBD is affecting their body. Some medications are used in the short term to stop inflammation, and others are used long-term to prevent flare-ups of symptoms.

Several different types of medications are used to treat IBD. They include:

Lifestyle changes may also help for some people. This includes stopping smoking, adopting a nutritious eating plan, meditation or mindfulness, stress reduction, and exercise. There is no one overall plan, but rather, people with IBD will work with their healthcare providers to incorporate behaviors that support their health.

Surgery is also used to treat IBD. There are several different types of surgery used and depend on which form of IBD is diagnosed and which part of the digestive system is involved.

Surgery for Crohn’s disease can include:

  • Resection, which is the removal of an inflamed part of the intestine

  • Strictureplasty, which is used to widen a portion of the intestine that is narrowed from scar tissues

  • Proctocolectomy (also called an ileoanal anastomosis or straight pull-through), which is when the large intestine is removed, and the small intestine is connected to the anus

  • Ostomy surgery, where a portion of the intestine is removed, and a stoma is created on the abdomen for stool to leave the body

Surgery for ulcerative colitis can include:

  • Proctocolectomy with the creation of a pelvic pouch (also called an ileal pouch-anal anastomosis, IPAA, or J-pouch), in which the large intestine is removed, and the last part of the small intestine is used to create a rectum and attached to the anus

  • Proctocolectomy with the creation of an ileostomy, where the large intestine is removed, and a stoma is created on the abdomen for stool to leave the body

IBD Complications

IBD causes inflammation, which can affect other parts of the body. It can also lead to complications inside and outside the digestive system. Not everyone who lives with IBD develops complications. Working with a healthcare provider to understand risks and if it is possible to prevent complications is an important part of living with IBD.

Complications within the digestive system can include:

Symptoms and conditions outside of the intestine may include:

Related: Risks of Untreated Crohn's Disease

Living With IBD

A diagnosis of IBD can bring on many challenges and emotions. It's important to acknowledge that this condition affects a person in all aspects of their life. Every person will need to learn how to manage the disease's symptoms and cope with how it affects daily life.

In recent years, it's been better understood that IBD affects mental health and that people with IBD are at increased risk of anxiety, depression, and post-traumatic stress or post-traumatic stress disorder (PTSD).

For that reason, every person with IBD will want to institute their own care plan to help cope with all of the challenging parts of this condition. This can include:

Many resources are available to get more information and to meet other people affected by these diseases. Patient advocacy groups, whether national or local, are good places to start finding information and support. People with IBD can speak to their healthcare team or ask at their local hospital or IBD center about the resources available.

Related: Leading IBD Charities & Organizations

How to Manage IBD

IBD will need to be managed over a lifetime. There is no way to reverse or cure these conditions. However, there are many ways to manage them.

The most important part of managing IBD is in reducing the inflammation that it causes. It is the inflammation that leads to complications both inside and outside of the digestive system. For many people with IBD, that means finding a medication that reduces symptoms and gets them into remission, and taking that medication consistently.

People with IBD may also want to avoid triggers associated with their flare-ups. There is not enough evidence concerning what causes flare-ups, but there are still measures people with IBD can take to avoid symptoms or cope with them when they do happen.

Avoiding triggers may include:

  • Avoiding foods that may cause gas and bloating (such as carbonated drinks)

  • Avoiding fatty, highly processed, and fast foods

  • Drinking enough water

  • Getting family-planning counseling from a healthcare provider

  • Keeping a food and symptom log to find any patterns

  • Putting stress reduction or stress mitigating tools in place (such as meditation)

  • Seeking mental healthcare when needed

  • Taking vitamins or supplements as recommended by a healthcare provider

  • Working with a dietitian to develop a nutritious eating plan


Irritable bowel syndrome (IBS) and IBD have many similar symptoms. but they are two different conditions with distinct treatments. People can live with both IBD and IBS at the same time. It may be difficult to determine which condition is causing symptoms.

IBD is an immune-mediated condition. IBS is a disorder of gut-brain interaction. People who have IBD and who still have symptoms even when the disorder is in remission may also have IBS.

IBS does not cause symptoms of fever or rectal bleeding. It is often treated with lifestyle and dietary changes. Some people may find that medications are needed to control symptoms. Surgery is not used as a treatment for IBS.

Related: Inflammatory Bowel Disease (IBD) vs. Irritable Bowel Syndrome (IBS)

When to Contact a Healthcare Provider

People who have symptoms of IBD (persistent diarrhea, abdominal pain, or bloody stools) should see a healthcare provider for an evaluation. A diagnosis of IBD can take time, so it’s important not to delay seeking care. 

When signs or symptoms of IBD worsen or return after a time of remission, contact your healthcare provider. There may be a need for testing to determine the cause and make changes to your treatment plan.

In most cases, IBD is not considered a life-threatening or fatal condition. However, some signs and symptoms are a reason to seek care in the emergency department. This may include:

  • Lack of bowel movements

  • Being dizzy or light-headed

  • Dehydration (extreme thirst, dark urine, or passing no urine)

  • Not being able to eat or drink anything

  • Severe abdominal pain

  • Vomiting repeatedly or after eating or drinking


IBD is a group of chronic disorders. Most people who live with one of these disorders will need to manage it throughout their lifetime with medications, lifestyle changes, and surgery. IBD affects the entire body, so it’s important to have a team of healthcare providers that can help in screening for and managing potential complications.

The symptoms of IBD may come and go. Being mindful of any new or changing signs and reporting them to a healthcare provider is key.

Read the original article on Verywell Health.