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About Crohn's Disease
Crohn's Disease (CD) is an ailment that creates
Chronic Inflammation in the
digestive system; it can affect any part of the digestive system from the mouth to the
Anus and affects approximately one million people in the United States and 27–48 per 100,000 people in Europe with numbers in all areas rising. Crohn's Disease, along with
Ulcerative Colitis are commonly referred to as
Inflammatory Bowel Disease, or IBD.
The exact cause and disease mechanisms are not fully understood, but it is thought to be caused by multiple factors. Microbes, environment, genetic status, and immunology are factors that can affect Crohn's Disease susceptibility and disease progression.
Crohn's Disease has a
Genetic link (over 30 genes have been discovered so far); if a close family member has Crohn's Disease, you are at increased risk of having an IBD. Studies indicate a risk between 10%-20% [this number can vary depending on gene mutation(s)].
Crohn's Disease is most common in Caucasians and less often diagnosed in Asians and African Americans.
[14]
Crohn's Disease is NOT Irritable Bowel Syndrome (IBS) (see
IBD v IBS). Crohn's Disease must be differentiated from other conditions which on the surface may have similar symptoms such as: Ulcerative Colitis,
IBS,
Clostridium difficile Infection, Parasite Infection, etc.
See Also: Crohn's Disease vs. Ulcerative Colitis.
It is yet unknown how important a role diet plays in Crohn's Disease but certain foods definitely aggravate symptoms. Crohn's Disease was once portrayed as an autoimmune disease but many researchers are moving away from that categorization. Crohn's Disease is now widely considered a disease of Immune System Deficiency or Immune System Dysregulation.[3]
Symptoms
Crohn's Disease symptoms tend to first manifest in the teens or twenties, but can occur at any age. Crohn's Disease is typically a chronic, relapsing condition that cycles through periods of
Remission and
"Flare-Ups". Crohn's Disease often exhibits a high patient-to-patient variability in terms of symptoms and disease course. Crohn's Disease is often difficult to diagnose because many symptoms are common to other conditions. While symptoms can vary significantly between sufferers, typical symptoms of Crohn's Disease often include:
*
(Independent conditions / diseases that often co-occur with Crohn's Disease are listed in parentheses and italics)
Abdomen
Anus / Rectal
Blood Tests**For Other Blood Tests Check the Wiki Page: Blood test codes and results explained
Bones / Joints
Bowel Movements / Defecation / Stool
Eye
Mouth / Oral
Psychiatric / Mental State / Mood / Affect
Skin
Stomach / Upper GI
Systemic / Body as a Whole
* Some people have all these symptoms, some only have one or two.
Types of Crohn's Disease
Ileocolitis - Ileocolitis is the most common type of Crohn's disease and affects the
ileum,
terminal ileum, and colon. Those with Ileocolitis frequently experience diarrhea, pain and cramping in the lower right quadrant of the abdomen and periumbilical region (around the belly button), and weight loss. Due to the nature of Ileocolitis, it is important to have
Vitamin B12 and
Folate levels checked regularly to test for deficiency. As
Inflammation between the ileum and colon is usually continuous, the
ileocecal valve is usually also diseased.
Ileitis - Ileitis is much like Ileocolitis but only affects the ileum and terminal ileum. Those with Ileitis, like Ileocolitis, frequently experience diarrhea (large volume), pain in the lower right abdomen and periumbilical region, and weight loss. Those with Ileitis should have their Vitamin B12 and Folate levels tested.
Gastroduodenal Crohn's Disease - Gastroduodenal Crohn's Disease is characterized by inflammation in the
stomach and
duodenum. Common symptoms include weight loss, nausea, loss of appetite, pain in the middle of the abdomen, and occasionally vomiting. Gastroduodenal Crohn's Disease is often misdiagnosed as normal ulcer disease and a correct diagnosis is not made until symptoms worsen. As the jejunum is where most nutrients are absorbed, those with Gastroduodenal Crohn's Disease often experience malnutrition due to malabsorption.
[1]
Jejunoileitis - Jejunoileitis occurs when there is inflammation in the
jejunum. It is characterized by diarrhea, pain following eating, and abdominal pain.
Crohn's Colitis - Crohn's Colitis (Granulomatous Colitis) is Crohn's Disease that only affects the colon. It is characterized by bleeding from the rectum and diarrhea (lower volume but greater frequency). It differs from Ulcerative Colitis in that the inflammation will be patchy whereas Ulcerative Colitis is continuous as Crohn's Colitis doesn't necessarily involve the rectum whereas Ulcerative Colitis always does.
Categories of Crohn's Disease
There are three categories that each type of Crohn's Disease can fall into. These are:
- Stricturing - Stricturing Crohn's Disease can lead to strictures or narrowing of the intestine. This can in turn lead to Intestinal Obstruction.
- Penetrating - Penetrating Crohn's Disease can lead to Fistulae which are tunnels from the intestines to other areas of the body including the skin, bladder, and vagina.
- Inflammatory (sometimes referred to as non-penetrating, non-stricturing) - this category of disease produces Inflammation but no strictures of fistulae.
Extraintestinal Manifestations
Diagnosing Crohn's Disease
Crohn's disease can be difficult to diagnose. If you think you may be suffering from Crohn's disease, or another IBD, it may be helpful to keep a diary (see
diary inclusions) as this will help your doctor build up a picture of your symptoms, and ensure they take your concerns seriously.
Diagnostic Tests
Histologic Findings
Often a series of biopsies will be taken when a colonoscopy or like procedure is performed. The histologic findings of Crohn's Disease are highly variable and not all characteristics are usually seen.
[13] Findings may include:
- Areas of chronic inflammation, comprising increased lamina propria plasma cells and lymphocytes, in association with chronic architectural distortion with patchy, mild to severe, neutrophilic inflammation, including neutrophilic cryptitis, crypt abscesses, or erosions/ulcers
- Skip lesions comprising focal, patchy erosions or ulcers, vertical fissures, and fistulas
- The hint of "skip lesions" – Mucosal fragments from the same level of the colon have variable microscopic findings.
- Transmural inflammation with multiple lymphoid aggregates
- Granulomas - Granulomas are seen in only 10-40% of Crohn's Disease patients and can also be found in patients with tuberculosis or yersiniosis.
- Submucosal fibrosis and neuromuscular hyperplasia of submucosa
Blood Tests
There are a variety of blood tests that can help your doctor determine if you have Crohn's Disease or not. While none are 100% accurate, they can help pinpoint what is transpiring.
Other Tests
Disease Course
Crohn's Disease Symptomology is Often Cyclic -
The course of Crohn's Disease varies dramatically between patients. Often, symptoms wax and wane between "
Flare" and
Remission. Some patients have extended periods of remission, while others may live in a continuous flare and never fully achieve remission.
Dysregulated Immune Response Stimulates Inflammatory Processes -
In Crohns Disease, cells of the
Innate Immune System often do not respond appropriately to
Antigens in the GI Tract. Different gene mutations can cause the error in immune response to occur at different steps in the pathway, and some genetic factors implicated in Crohn's Disease are yet unknown. The general disease trend is an error (or errors) within the innate immune response to antigen which results in a dysregulation of the balance between pro-inflammatory
Cytokines [such as
Interleukin 1 (IL1),
Interleukin 6 (IL6),
Interleukin 12 (IL12),
Tumor Necrosis Factor alpha (TNF α), IFN-gamma] and anti-inflammatory cytokines [such as Interleukin 4 (IL4),
Interleukin 10 (IL10), Interleukin 11 (IL11)]. During a "flare" the inflammatory response goes unchecked and results in large amounts of pro-inflammatory factors to be activated.
Normal Immune Response to Pathogens:
In a normally functioning immune system, there exists a balance between pro-inflammatory and anti-inflammatory factors that are expressed at a baseline level (Figure 1A).
Upon stimulation with an infectious agent, the pro-inflammatory responders are co-activated- or followed shortly thereafter with upregulation of anti-inflammatory factor activity, and leads to a delicate interplay between pro-inflammatory and anti-inflammatory responses (Figure 1B).
When the threat (pathogen) has been cleared, the pro-inflammatory signals subside and the balance is slowly normalized (Figure 1C).
Crohn's Disease Response to Pathogens:
In Crohn's Disease, the immune response is dysregulated. The immune system may be stimulated inappropriately (i.e. to normal intestinal flora) and/or can ineffectively over-activate in response to a pathogen. Often, one or more of the mechanisms utilized for killing and removal of pathogens is ineffective. This can be in combination with an inefficient feedback mechanism to dampen the inflammatory/immune responses. The result of reduced pathogen-destruction combined with less effective anti-inflammatory signaling can trigger a vicious "pro-inflammatory cycle" typically seen in Crohn's Disease symptomatic "flares" (Figure 1D).
In the normally functioning immune response the activation of innate immunity in turn activates the adaptive immune system allowing a more specific (although delayed) response to the infecting agent. The adaptive immune system activates additional factors to stimulate both adaptive and innate immune responses. In Crohn's Disease, the anti-inflammatory mechanisms are reduced causing this pro-inflammatory cycling effect. Chronically active pro-inflammatory responses can cause tissue destruction and certain inflammatory factors can increase growth rates of microorganisms.
Crohn's Disease can Cause Strictures -
Many Patients Require Surgical Intervention
Treatment
There are many treatments available to alleviate the symptoms of Crohn's disease, reduce inflammation, induce remission, and minimize the likelihood of relapse. Unfortunately there is no cure as yet.
Drug Treatments
There are a variety of drug treatments available to control symptoms, help induce remission, and prevent relapse.
5-ASA
This is a class of drugs which are similar to aspirin, and have a similar anti-inflammatory effect. These drugs are poorly absorbed into the body, therefore they act on the surface of the intestines. This makes them relatively mild, and less likely to have side effects.
Mesalazine / mesalamine (
Apriso,
Asacol,
Lialda,
Pentasa)
Sulphasalazine
Corticosteroids
Immune System Suppressors
Biological Therapies
Antibiotics
Antidiarrheals
Over The Counter (OTC) Drug Treatments
There are also over the counter
drugs and remedies to make living with the symptoms easier.
Surgery
In some cases,
surgery may be required to remove particularly diseased sections of bowel. Half of adults with Crohn's Disease will require surgery with 10 years of diagnosis. In children, surgical rates are much higher, 34% of children undergo surgery within 5 years of diagnosis.[4]
Check out this external website for more information about Surgery for IBD.
HERE
Supplements
Some people may choose to use
supplements and complementary therapies, either as a stand alone treatment or to enhance other treatments.
Diets
Likewise, different
diets can be used to alleviate symptoms, or as a main course of treatment.
Alternative Treatments
Some people may choose to use
alternative treatments, either because they feel more comfortable doing so, or because conventional treatments have failed.
New and Future Treatments for Crohn's Disease
Various new and emerging treatments are currently being explored as possible effective treatments for Crohn's Disease and Crohn's-related symptoms.
-
Stem Cell (SC) Therapy
- An Opioid Antagonist,
Low Dose Naltrexone (LDN), previously used for treating Substance Abuse has shown promise in the treatment of Crohn's Disease.
It is important to discuss the different options with your doctor before deciding which course of treatment(s) to follow.
Risk of Relapse in Crohn's Disease
Patients with Crohn's Disease have extremely variable rates of symptom return following remission. There are multiple factors which contribute to a higher risk of relapse.
Gene Mutation(s) -
Certain genetic mutations correlate with more aggressive disease. For example, certain mutations in the
Nod2 / Card15 Gene is associated with earlier onset of symptoms and higher rates of surgery.
Age of Onset -
An earlier age of onset of symptoms (especially in young children) often correlates with more aggressive disease.
Treatment Course - "Top-Down" strategies in treating Crohn's Disease versus the traditional "Step-Up" approach, using aminosalicylates, antibiotics, immunosuppressants, to TNF - inhibitors.
Treatment Compliance - Higher rates of relapse were seen in patients that were less compliant with drug regimens.
Smoking - Smoking, or exposure to second-hand smoke is a well-established factor in decreasing periods of remission.
Blood Test Predictors -
Certain blood test predictors correlate with greater probability of relapse, these include:
- 1). Elevated
CRP (C-Reactive Protein) - Levels 20mg/L and above.
- 2). Elevated Neutrophils - 4 x 10^9 /L and above.
- 3). Low
Hemoglobin (Hgb) - Below 12.0 g/dL.
Living with Crohn's disease
References
Popular Threads Discussing Crohn's Disease
