Table of ContentsView AllTable of ContentsGenesAutoimmune ReactionEnvironmental TriggersDebunking Common MythsNext in Crohn’s Disease GuideHow Crohn’s Disease Is Diagnosed
Table of ContentsView All
View All
Table of Contents
Genes
Autoimmune Reaction
Environmental Triggers
Debunking Common Myths
Next in Crohn’s Disease Guide
Scientists don’t know exactly what causesCrohn’sdisease. However, they think it may involve a complex interaction of several factors, including genes, the immune system, and environmental triggers.
Crohn’s diseasetends to run in families and certain gene variations may put you at greater risk for developing it. An abnormal immune response may trigger chronic inflammation in your digestive tract that doesn’t heal. In addition, certain medications geographic locations, and smoking, may all increase your risk.
© Verywell, 2018
It’s taking time to pinpoint the exact nature of how Crohn’s disease may be inherited because while it has been known for some time that it runs in families, it was not exactly clear how that occurred.
Scientists have now identified more than 200genevariations that may be involved in the development of Crohn’s disease.
The main genes associated with Crohn’s are involved in immune function and help destroy digestive tract bacteria. However, most of these gene variations are thought to change the amount of gene activity and alter the immune system’s response, causing it to attack healthy cells, leading to chronic inflammation. How these variations influence disease risk remains unknown, but they account for only a small percentage of the total Crohn’s disease risk.
Studies show that between 5% and 20% of people with IBD have a close family member (e.g., parent or sibling) with the disease, increasing their risk of developing it.Also, Crohn’s is most prevalent in people of Eastern European backgrounds, especially Jewish people of European descent.
However, it’s thought that having the genes alone isn’t enough to develop Crohn’s disease and that there must also be one or more “triggers” that lead to the development of IBD. Because not everyone who carries the genes associated with Crohn’s disease eventually develops the condition, it’s understood that the cause includes more than a hereditary factor.
Crohn’s disease is often described as anautoimmune condition. This is because the disease is thought to stem from a disruption in the immune system.
This is why it is often treated with medications that suppress the immune system. When the immune system is tamped down, it can decrease the effects that the overactivity is having on the digestive system.
The misfire in the immune system may come from a type of allergic response that causes the release of an abundance ofeosinophils.Eosinophils are cells that fight off allergic responses. In doing so, they release toxic compounds. Research shows a relationship between people with Crohn’s disease and an excess amount of eosinophils in their blood and tissues.
Even after the genetic and immune system factors are taken into account, there still may be more to the development of Crohn’s disease.
It’s currently unknown how many of these triggers exist or how they may interact with the other potential causes of Crohn’s disease. A few possible triggers include:
Previous Gastrointestinal Infections
People with previousSalmonellaorCampylobacterinfections have an increased risk of IBD.These infections may trigger an immune response that changes thegut microbiomeand leads to chronic inflammation.
A 2009 study followed 13,148 exposed people for up to 15 years. Those who had either infection were almost three times as likely to develop IBD over 15 years compared to those uninfected. The risk was highest the first year after infection but remained elevated for 15 years.
Researchers don’t know exactly why people develop Crohn’s disease, which has led to many incorrect ideas about what can cause it.
Diet and Stress
These were thought to play major roles in the development of Crohn’s disease, but do not cause IBD. Stress reduction and dietary modifications can be a part of treatment, but these lifestyle factors are neither causes nor cures for IBD.
Some research indicates that a high-fat diet (saturated fats, red meat, or animal fats) may increase the risk of developing IBD.
Several specialized diets may help alleviate symptoms and reduceflare-ups.
Some of these may include:
Age
Although Crohn’s disease is commonly diagnosed between the ages of 15 and 40 years, it can be diagnosed at any age, including children.
Maintain Your Medication RoutineSymptoms may be intermittent but it’s important to take regular medication to avoid flare-ups. Some factors that can cause symptoms to flare up include missing an IBD medication, taking antibiotics, smoking, and feeling stressed.Talk with your healthcare provider about what causes your flaresand how to manage symptoms.
Maintain Your Medication Routine
Symptoms may be intermittent but it’s important to take regular medication to avoid flare-ups. Some factors that can cause symptoms to flare up include missing an IBD medication, taking antibiotics, smoking, and feeling stressed.Talk with your healthcare provider about what causes your flaresand how to manage symptoms.
Summary
Although the exact cause of Crohn’s disease remains unknown, researchers have suggested that genetics, autoimmune reactivity, and certain environmental triggers contribute to its development. Dietary and some lifestyle modifications may help alleviate symptoms but do not cause or cure this disease.
16 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Shi HY, Ng SC.The state of the art on treatment of Crohn’s disease. J Gastroenterol. 2018;53(9):989-998. doi:10.1007/s00535-018-1479-6Crohn’s & Colitis Foundation.Living with Crohn’s disease.MedlinePlus.Crohn’s disease.Crohn’s & Colitis Foundation.Causes of Crohn’s disease.Cedars-Sinai.Crohn’s disease.Katsanos KH, Zinovieva E, Lambri E, Tsianos EV.Eosinophilic-Crohn overlaps colitis and review of the literature.J Crohns Colitis. 2011;5(3):256-61. doi:10.1016/Feuerstein JD, Cheifetz AS.Crohn disease: epidemiology, diagnosis, and management.Mayo Clin Proc. 2017;92(7):1088-1103. doi:10.1016/j.mayocp.2017.04.010Ko Y, Butcher R, Leong RW.Epidemiological studies of migration and environmental risk factors in the inflammatory bowel diseases.World Journal of Gastroenterology.2014;20(5):1238–1247.Cornish JA, Tan E, Simillis C, et al.Risk of oral contraceptives in the etiology of inflammatory bowel disease: a meta-analysis.Am J Gastroenterol.2008;103(9):2394-400. doi: 10.1111/j.1572-0241.2008.02064.x.Gradel KO, Nielsen HL, Schonheyder HC, et al.Increased short- and long-term risk of inflammatory bowel disease after Salmonella or Campylobacter.Gastroenterology. 2009;137(2):495-501.Gradel KO, Nielsen HL, Schonheyder HC, et al.Increased short- and long-term risk of inflammatory bowel disease after Salmonella or Campylobacter.Gastroenterology. 2009;137(2):495-501.Mayo Clinic.Crohn’s disease.Owczarek D, Rodacki T, Rodacka RD, et. al.Diet and nutritional factors in inflammatory bowel disease.World J Gatroenterol.2016.21;22(3):895-905. doi:10.3748/wjg.v22.i3.895Crohn’s & Colitis Foundation.Special IBD diets.NHS inform.Crohn’s disease.Crohn’s & Colitis Foundation.Managing flares and IBD symptoms.Additional ReadingHalme L., Paavola-Sakki P., Turunen U., Lappalainen M., Farkkila M., Kontula K.Family and twin studies in inflammatory bowel disease.World J Gastroenterol. 2006;12:3668–3672.Liu JZ, Anderson CA.Genetic studies of Crohn’s disease: past, present and future.Best Practice & Research Clinical Gastroenterology. 2014;28:373-386.Zhou M, He J, Shen Y, Zhang C, Wang J, Chen Y.New frontiers in genetics, gut microbiota, and immunity: a Rosetta Stone for the pathogenesis of inflammatory bowel disease.BioMed Research International.2017;2017:8201672.
16 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Shi HY, Ng SC.The state of the art on treatment of Crohn’s disease. J Gastroenterol. 2018;53(9):989-998. doi:10.1007/s00535-018-1479-6Crohn’s & Colitis Foundation.Living with Crohn’s disease.MedlinePlus.Crohn’s disease.Crohn’s & Colitis Foundation.Causes of Crohn’s disease.Cedars-Sinai.Crohn’s disease.Katsanos KH, Zinovieva E, Lambri E, Tsianos EV.Eosinophilic-Crohn overlaps colitis and review of the literature.J Crohns Colitis. 2011;5(3):256-61. doi:10.1016/Feuerstein JD, Cheifetz AS.Crohn disease: epidemiology, diagnosis, and management.Mayo Clin Proc. 2017;92(7):1088-1103. doi:10.1016/j.mayocp.2017.04.010Ko Y, Butcher R, Leong RW.Epidemiological studies of migration and environmental risk factors in the inflammatory bowel diseases.World Journal of Gastroenterology.2014;20(5):1238–1247.Cornish JA, Tan E, Simillis C, et al.Risk of oral contraceptives in the etiology of inflammatory bowel disease: a meta-analysis.Am J Gastroenterol.2008;103(9):2394-400. doi: 10.1111/j.1572-0241.2008.02064.x.Gradel KO, Nielsen HL, Schonheyder HC, et al.Increased short- and long-term risk of inflammatory bowel disease after Salmonella or Campylobacter.Gastroenterology. 2009;137(2):495-501.Gradel KO, Nielsen HL, Schonheyder HC, et al.Increased short- and long-term risk of inflammatory bowel disease after Salmonella or Campylobacter.Gastroenterology. 2009;137(2):495-501.Mayo Clinic.Crohn’s disease.Owczarek D, Rodacki T, Rodacka RD, et. al.Diet and nutritional factors in inflammatory bowel disease.World J Gatroenterol.2016.21;22(3):895-905. doi:10.3748/wjg.v22.i3.895Crohn’s & Colitis Foundation.Special IBD diets.NHS inform.Crohn’s disease.Crohn’s & Colitis Foundation.Managing flares and IBD symptoms.Additional ReadingHalme L., Paavola-Sakki P., Turunen U., Lappalainen M., Farkkila M., Kontula K.Family and twin studies in inflammatory bowel disease.World J Gastroenterol. 2006;12:3668–3672.Liu JZ, Anderson CA.Genetic studies of Crohn’s disease: past, present and future.Best Practice & Research Clinical Gastroenterology. 2014;28:373-386.Zhou M, He J, Shen Y, Zhang C, Wang J, Chen Y.New frontiers in genetics, gut microbiota, and immunity: a Rosetta Stone for the pathogenesis of inflammatory bowel disease.BioMed Research International.2017;2017:8201672.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Shi HY, Ng SC.The state of the art on treatment of Crohn’s disease. J Gastroenterol. 2018;53(9):989-998. doi:10.1007/s00535-018-1479-6Crohn’s & Colitis Foundation.Living with Crohn’s disease.MedlinePlus.Crohn’s disease.Crohn’s & Colitis Foundation.Causes of Crohn’s disease.Cedars-Sinai.Crohn’s disease.Katsanos KH, Zinovieva E, Lambri E, Tsianos EV.Eosinophilic-Crohn overlaps colitis and review of the literature.J Crohns Colitis. 2011;5(3):256-61. doi:10.1016/Feuerstein JD, Cheifetz AS.Crohn disease: epidemiology, diagnosis, and management.Mayo Clin Proc. 2017;92(7):1088-1103. doi:10.1016/j.mayocp.2017.04.010Ko Y, Butcher R, Leong RW.Epidemiological studies of migration and environmental risk factors in the inflammatory bowel diseases.World Journal of Gastroenterology.2014;20(5):1238–1247.Cornish JA, Tan E, Simillis C, et al.Risk of oral contraceptives in the etiology of inflammatory bowel disease: a meta-analysis.Am J Gastroenterol.2008;103(9):2394-400. doi: 10.1111/j.1572-0241.2008.02064.x.Gradel KO, Nielsen HL, Schonheyder HC, et al.Increased short- and long-term risk of inflammatory bowel disease after Salmonella or Campylobacter.Gastroenterology. 2009;137(2):495-501.Gradel KO, Nielsen HL, Schonheyder HC, et al.Increased short- and long-term risk of inflammatory bowel disease after Salmonella or Campylobacter.Gastroenterology. 2009;137(2):495-501.Mayo Clinic.Crohn’s disease.Owczarek D, Rodacki T, Rodacka RD, et. al.Diet and nutritional factors in inflammatory bowel disease.World J Gatroenterol.2016.21;22(3):895-905. doi:10.3748/wjg.v22.i3.895Crohn’s & Colitis Foundation.Special IBD diets.NHS inform.Crohn’s disease.Crohn’s & Colitis Foundation.Managing flares and IBD symptoms.
Shi HY, Ng SC.The state of the art on treatment of Crohn’s disease. J Gastroenterol. 2018;53(9):989-998. doi:10.1007/s00535-018-1479-6
Crohn’s & Colitis Foundation.Living with Crohn’s disease.
MedlinePlus.Crohn’s disease.
Crohn’s & Colitis Foundation.Causes of Crohn’s disease.
Cedars-Sinai.Crohn’s disease.
Katsanos KH, Zinovieva E, Lambri E, Tsianos EV.Eosinophilic-Crohn overlaps colitis and review of the literature.J Crohns Colitis. 2011;5(3):256-61. doi:10.1016/
Feuerstein JD, Cheifetz AS.Crohn disease: epidemiology, diagnosis, and management.Mayo Clin Proc. 2017;92(7):1088-1103. doi:10.1016/j.mayocp.2017.04.010
Ko Y, Butcher R, Leong RW.Epidemiological studies of migration and environmental risk factors in the inflammatory bowel diseases.World Journal of Gastroenterology.2014;20(5):1238–1247.
Cornish JA, Tan E, Simillis C, et al.Risk of oral contraceptives in the etiology of inflammatory bowel disease: a meta-analysis.Am J Gastroenterol.2008;103(9):2394-400. doi: 10.1111/j.1572-0241.2008.02064.x.
Gradel KO, Nielsen HL, Schonheyder HC, et al.Increased short- and long-term risk of inflammatory bowel disease after Salmonella or Campylobacter.Gastroenterology. 2009;137(2):495-501.
Mayo Clinic.Crohn’s disease.
Owczarek D, Rodacki T, Rodacka RD, et. al.Diet and nutritional factors in inflammatory bowel disease.World J Gatroenterol.2016.21;22(3):895-905. doi:10.3748/wjg.v22.i3.895
Crohn’s & Colitis Foundation.Special IBD diets.
NHS inform.Crohn’s disease.
Crohn’s & Colitis Foundation.Managing flares and IBD symptoms.
Halme L., Paavola-Sakki P., Turunen U., Lappalainen M., Farkkila M., Kontula K.Family and twin studies in inflammatory bowel disease.World J Gastroenterol. 2006;12:3668–3672.Liu JZ, Anderson CA.Genetic studies of Crohn’s disease: past, present and future.Best Practice & Research Clinical Gastroenterology. 2014;28:373-386.Zhou M, He J, Shen Y, Zhang C, Wang J, Chen Y.New frontiers in genetics, gut microbiota, and immunity: a Rosetta Stone for the pathogenesis of inflammatory bowel disease.BioMed Research International.2017;2017:8201672.
Halme L., Paavola-Sakki P., Turunen U., Lappalainen M., Farkkila M., Kontula K.Family and twin studies in inflammatory bowel disease.World J Gastroenterol. 2006;12:3668–3672.
Liu JZ, Anderson CA.Genetic studies of Crohn’s disease: past, present and future.Best Practice & Research Clinical Gastroenterology. 2014;28:373-386.
Zhou M, He J, Shen Y, Zhang C, Wang J, Chen Y.New frontiers in genetics, gut microbiota, and immunity: a Rosetta Stone for the pathogenesis of inflammatory bowel disease.BioMed Research International.2017;2017:8201672.
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