Crohn's Disease

: What to Know

As defined by the U.S. National Library of Medicine, Crohn’s disease is a complex chronic disorder that affects the digestive system. The disease is an autoimmune response that causes excess inflammation in the intestinal walls, most notably in the lower regions of the small intestine, as well as some areas of the colon or large intestine. The inflammation can manifest itself in any part of the digestive system, ranging from the mouth to the anus.

Crohn’s disease is just one of several diseases falling under inflammatory bowel disease (IBD), as well as one of the most common of its forms. For many years, there wasn’t a lot of research or information about Crohn’s disease. Inflammatory bowel diseases were lumped together in a group. 

Back in 1875 ulcerative colitis (UC) was first defined by two English physicians named Wilks and Moxon. Ulcerative colitis can also cause chronic inflammation of the intestinal lining. However, unlike Crohn’s disease, which spreads out and can affect other parts of the digestive system, ulcerative colitis tends to localize its inflammation around the colon.

Then, an autopsy performed in a 42-year-old woman who died after many months of suffering diarrhea and fever showed a “transmural ulcerative inflammation of the colon and terminal ileum.” Though Wilks and Moxon first described this as simple ulcerative colitis, it would be renamed roughly a century later into what is now known as Crohn’s disease.

Crohn’s disease was first adequately described in 1932 by Drs. Burril Crohn, Leon Ginzberg, and Gordon D. Oppenheimer. The three doctors had collected data from 14 patients who were supposedly suffering from a disease in the small intestine that they previously only called intestinal tuberculosis. Upon studying the significant symptoms that all 14 patients displayed, they realized that these were not hallmarks of tuberculosis nor that of any other known disease. The group of doctors then described the illness as something new and named it Crohn’s disease. While treatments have improved in the subsequent 90 days, there still isn’t a known cure for the disease.

The inflammation caused by Crohn’s disease compels tissues to become thick and swollen, to the point that some surface areas in the digestive system will develop open sores. The inflammation itself leads to abdominal pain, weight loss, fatigue, and severe diarrhea, along with malnutrition. As the inflammation itself spreads deep into the affected bowel tissue, the patient can experience debilitating pain, and in turn, lead to complications that can threaten their lives. These complications can include intestinal blockages and ulcers. The disease, though it begins gradually, can worsen over time, especially when its symptoms aren’t adequately addressed. In some cases, Crohn’s disease can even lead to chronic bleeding, anemia, and eye and skin issues.

Patients who have Crohn’s disease experience a cycle of flare-ups wherein the disease’s symptoms worsen before going into remission once again. The cycle itself can happen multiple times throughout a person’s life. This cycle is especially evident with individuals who have gastrointestinal tract inflammation, who suffer greatly during a flare-up of the disease. Patients may feel more at ease or even normal during times of remission.

Roughly three million Americans are affected by some form of inflammatory bowel disorder. And more than 700,000 of those are diagnosed with Crohn’s disease. According to the Crohn’s and Colitis Foundation of America, this number grows steadily as new people are diagnosed. The disease affects both adults and children, and symptoms and complications for each of these people may differ.

As Crohn’s disease’s symptoms manifest differently in different people, there are also different types of the disease.

  • Ileocolitis – This is considered as the most common form of Crohn's disease. It primarily affects the terminal ileum (the end of the small intestine) and the large intestine or colon. Symptoms include diarrhea, cramping, significant pain in the middle or lower right side of the abdomen, and weight loss.
  • Ileitis – Only the ileum is affected in this type of Crohn’s disease. Symptoms are similar to that of ileocolitis, but in severe cases, complications arise, such as fistulas and inflammatory abscesses. Abscesses typically are found at the right-side lower region of the abdomen.
  • Gastroduodenal Crohn’s disease – This type of Crohn’s affects the stomach and upper portion of the small intestine. Symptoms include nausea, vomiting, loss of appetite, and weight loss.
  • Jejunoileitis – Patchy areas of inflammation characterize this specific form of Crohn’s. The patches are typically located in the upper half of the small intestine. Mild to intense abdominal pain and cramps may occur following meals. Diarrhea also occurs, and fistulas may form in more severe cases, especially when the inflammation period is prolonged.
  • Crohn’s (Granulomatous) Colitis – Only the colon is affected in this variety of Crohn’s disease. Symptoms are similar to other forms of the disease but can be more severe, including diarrhea, rectal bleeding, infection around the anus (often abscesses, fistulas, and ulcers). Skin lesions and joint pains may manifest in this variety of Crohn’s more so than in others.

To correctly assess which type of Crohn’s disease a patient may have, a thorough examination and diagnosis by a medical professional are necessary.

As mentioned, the signs and symptoms of Crohn’s disease may vary between patients. The experience of having Crohn’s disease will depend upon which part of the gastrointestinal tract is affected by the illness.

Crohn’s can affect both children and adults, and signs of the disease may start at any age. Research has shown that the symptoms often begin to show among adolescents or young adults who are 15-35 years old.

Because Crohn’s is considered a chronic disease, people experience cycles wherein there will be active symptoms called flares followed by periods of remission. During flares, symptoms manifest, but the most notable one remains gastrointestinal tract inflammation, the hallmark of Crohn’s disease. The disease can affect virtually any area of the G.I. tract, from the mouth, all the way to the anus. Issues that Chron’s can cause in the G.I. tract include:

  • Rectal bleeding
  • Urgent need to move bowels
  • Reoccurring or persistent diarrhea. This can range from mild to severe diarrhea, and there may be pus, mucus, or blood.
  • Significant abdominal cramps and pain. The pain levels may vary between individuals, but often, the pain will be on the lower right side of the abdomen.
  • A sensation of having incomplete bowel evacuation
  • And constipation, leading to potential bowel obstructions

These are some of the most common symptoms of Crohn’s. However, the disease also has several secondary signs or complications that aren’t restricted to areas in or around the G.I. tract. Other symptoms that may be evident in the patient’s overall health and affect a patient’s quality of life include:

  • Anemia (paleness and blood loss)
  • Redness or pain in the eyes
  • Fatigue or continually feeling exhausted. Individuals start to feel extremely tired
  • Pain, swelling, or soreness in the joints.
  • Kidney stones
  • Osteoporosis
  • A sensation of nausea, accompanied by a loss of appetite
  • Skin inflammation, mainly red and tender bumps, rashes, and sores
  • Delayed growth and development
  • Mouth sores or ulcers
  • Night sweats
  • Loss of normal menstrual cycle
  • On rare occasions, patients might suffer from liver complications, primary sclerosing cholangitis, or cirrhosis

In severe cases, some complications of Crohn’s disease may lead to:

  • Fissures – These are tears in the lining of the anus, which create bleeding or blood in the stool, especially during a bowel movement.
  • Fistulas – These are also caused by the inflammation and are common around the anus. Fistulas refer to an abnormal channel forming from one intestine to another, or traveling from the intestine to the bladder, vagina, or the skin. These need immediate medical attention if they develop.
  • Stricture – This refers to the narrowing of the intestine from the chronic inflammation.
  • Abscess – This term refers to a collection of pus forms in the abdomen, pelvis, or in the anal area.
  • Perforated bowel – In some cases, the chronic inflammation becomes so severe that the walls of the intestine weaken, and a hole develops there.
  •  Malnutrition – As the body is unable to properly absorb the nutrients in the food due to the affected areas of the G.I. tract, a person can develop deficiencies of necessary vitamins and minerals.

For some researchers, the stress involved in living with Crohn’s disease and its symptoms may exacerbate symptoms. Some studies suggest a connection between smoking and Crohn’s, as some frequent smokers develop worse or more frequent flare-ups than non-smokers.

There is also the possibility that having Crohn’s disease may increase the likelihood of the patient developing G.I. cancer. Colorectal cancer risks are increased in people with Crohn’s and may increase further as time goes by.

To this day, doctors aren’t sure what specifically causes Crohn’s disease. Numerous risk factors may be associated with getting the disease. Initially it was thought that stress and diet might contribute to the onset of Crohn’s, but doctors have since discovered that those are aggravating factors rather than causes. Research so far suggests that the compound causes may be a combination of genetic, environmental, and lifestyle factors.

Over 700,000 people in America are believed to have Crohn’s disease. The Centers for Disease Control and Prevention indicates that it affects anywhere between 26 to 199 people for every 100,000. Both men and women are likely to be affected, and it can occur at any age. However, Crohn’s is seen as more prevalent among adolescents and adults, mainly between ages 15 and 35. Heredity and the immune system are seen as significant factors in the development of Crohn’s disease. Environmental triggers such as medication, pollution, and excessive usage of antibiotics get also considered as possible causes.

  • Immune System

Some studies speculate that a virus or bacterium may be responsible for the disease by triggering an autoimmune response in the body. Instead of the normal immune response of fighting off the invading microbes, the immune system begins attacking the digestive tract and causing inflammation. White blood cells build up in the gut’s lining, leading to ulcers and bowel injury.

  • Genetic Factors

Crohn’s appears more common among people who have family members that also have the disease, so genetics may play a role in increasing the risk of getting Crohn’s disease. Even having a family history of irritable bowel disorders could increase the risk of developing Crohn’s. At least 15% of affected individuals also have a parent or a sibling who also has Crohn’s disease.

According to the U.S. National Library of Medicine’s Genetics Home Reference, many genes that are related to Crohn’s disease (including NOD2, ATG16L1, IL23R, and IRGM) produce proteins that are involved in immune system function. Variations in the genes can disrupt autophagy, changing the way the immune system responds to digestive system bacteria. When triggered by or combined with environmental factors, inflammation occurs and results in the symptoms that are characteristic of Crohn’s.

  • Ethnicity and Environment

Crohn’s can affect virtually any ethnic group, but white people, including those of Eastern European Jewish descent, have the highest risk. There is also an increasing incidence of black people living in North America and the United Kingdom getting the disease. 

Living in urban or industrialized areas may not necessarily cause Crohn’s disease, but there are more occurrences of the disease in these areas than other places. In terms of geographic distribution, most IBDs can be found in developed countries and northern climates. However, some studies suggest that the patterns may be changing, mostly due to the environment. Ethnic groups that immigrated to the U.S. after coming from countries with low incidences showed that they now adopt higher rates of developing the disease.

  • Age

Most people that develop Crohn’s disease are typically diagnosed before they’re 30 years old. The condition can be diagnosed at a younger age, but it’s rare to have occurrences of the disease among children younger than eight years old. One-third of children with Crohn’s disease also grow to a shorter final adult height because of the condition.

To truly diagnose whether or not an individual has Crohn’s disease, doctors have to perform numerous exams and tests to seek out signs of bleeding and to rule out underlying causes. Because of the genetic and environmental factors, physicians must consider family and patient history as well. They need to study a patient’s background, where they’re from, and whether or not their families had any incidences of IBD or Crohn’s disease in particular.

Specific tests can be performed to aid healthcare providers in diagnosing or eliminating the possibility of Crohn’s disease.

  • Blood tests – These include analyses that look into anemia or infection. Anemia is a condition where there aren’t enough red blood cells to oxygenate one’s tissues. However, experts don’t currently recommend using genetic testing or antibody testing for Crohn’s disease. A fecal occult blood test is also another test that may be performed; the patient needs to provide stool samples so the doctor can check if there is any hidden blood.
  • Colonoscopy – Through this procedure, doctors will be able to view the entire colon and the end of the ileum. They can check for signs of inflammation, as well as take small samples for laboratory confirmation of a diagnosis.
  • Computerized tomography – A CT scan may be necessary to view the entire bowel along with the tissues outside of it. CT enterography may provide better images of the small intestine.
  • Magnetic resonance imaging – An MRI scanner can create detailed images of organs and tissues, making it useful for evaluating the anal area through a pelvic MRI.

Capsule endoscopy – The patient swallows a capsule that contains a tiny camera. The camera travels down the G.I. tract and can take photographs of the small intestine, which a doctor can then study for signs of the disease.

As mentioned previously, there is currently no cure available for Crohn’s disease. However, there are available treatments and medication that can help control its symptoms, especially during the cycle of flare-ups and remissions. Procedures will depend on where the inflammation is, how far along the disease has developed, any complications present, and the patient’s previous responses to prior treatments.


  • Corticosteroids – Prednisone and budesonide can help reduce inflammation in the body. However, they won’t always work for everyone with Crohn’s disease. These are only used for short-term improvement of symptoms.
  • Oral 5-aminosalicylates – These include sulfasalazine and mesalamine. Though widely used in the past, these are also now considered of limited benefit.
  • Azathioprine or mercaptopurine – These are immunosuppressants for IBD. A patient will need careful guidance from their physician to watch out for adverse side-effects.
  • Infliximab, adalimumab, and certolizumab pegol – These are tumor necrosis factor inhibitors that neutralize specific immune system proteins that are part of the body’s inflammatory response.
  • Methotrexate – This is sometimes used for patients who don’t respond well to other medications.

Diet & Lifestyle:

Changing one’s diet can help reduce symptoms. Doctors recommend:

  • Avoiding carbonated drinks
  • Avoiding popcorn, vegetable skins, nuts, and other foods with very high fiber content
  • Staying hydrated and drinking plenty of liquids
  • Eating smaller meals rather than large ones
  • Maintaining a food diary to keep track of what you consume

Depending on the type of Crohn’s, a doctor might also recommend a diet that’s high calorie, lactose-free, low fat, low fiber, and low salt. It’s important to talk with one’s doctor about the right diet for your symptoms.

Therapy and Procedures:

  • Nutrition therapy – This is a special diet given via a feeding tube wherein nutrients are injected straight into a vein to treat the disease.
  • Surgery – Assuming that all other methods have failed to relieve the symptoms of Crohn’s disease, a doctor may recommend surgery. While it won’t cure the disease, it can remove damaged portions of the digestive tract and reconnect healthy areas.
  • Biologic therapies – These are the most recently-developed treatments for IBD, not just Crohn’s disease. They are recommended for people with moderately to severely active symptoms that haven’t been alleviated by previous therapies.

There is still much to be learned about Crohn’s disease. Researchers are still conducting studies and clinical trials to test new treatments, interventions, and tests to detect and manage the disease. 

Understanding where the disease comes from is also vital, as there is no specific cause, just numerous risk factors. Therefore it’s critical for patients to also keep a close eye on their patient records and their diaries during treatment. It can give doctors a valuable glimpse into what could cause the disease.

Through the digitalization of patient and medical records, it’s now easier for doctors to keep track of their patients’ progress. They can look into their medical histories, and find new answers to what causes Crohn’s disease, and how they might potentially be able to treat it better.

People with Crohn’s who want to contribute to research can sign up for a PicnicHealth account to contribute their anonymized medical data to Crohn’s research.

Will the disease ever go away?

As IBD and Crohn’s disease are chronic, patients generally have the condition for life, but medication and treatment can help suppress and manage symptoms. You may go through periods of remission wherein the disease’s symptoms fade, but most patients remain on medication even if the disease is in remission.

Are there alternative treatments available if I don’t want surgery?

Surgery remains a significant treatment in the life of a Crohn’s disease patient—one-third of the people afflicted with it will need surgery. That means most people do manage their condition without surgery, through medication and lifestyle changes. Some people also seek alternative medical treatments, but experts recommend that patients consult closely with their physicians first before trying any alternative solutions.

What symptoms will signal an emergency?

Crohn’s disease can cause several embarrassing symptoms, but it can also become life-threatening very quickly. Strictures can occur and cause a bowel obstruction. It would feel like sharp abdominal pain but with no bowel movements. This is typically the only type of medical emergency possible from Crohn’s.

What are the possible side-effects of medication for Crohn’s?

People with Crohn’s disease are often put on powerful medication. You need to be aware of the possible side-effects they may have, including weight gain and anemia. Side-effects vary by medication, so it’s important to discuss with your doctor before taking medication.

Part of understanding and finding better treatments for Crohn’s disease is through the careful study of patient records and tests. PicnicHealth makes it easier to get your complete medical records to aid in managing Crohn’s disease. Visit to sign up for a free PicnicHealth account if you have Crohn’s.

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