Editing Enteritis

{{Short description|Inflammation of the small intestine}}
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{{Infobox medical condition (new)
| name = Enteritis
| synonyms =
| image = Crohn's ileitis - biopsy, intermed. mag.1.jpg
| caption = Tissue of the [[ileum]] with inflammatory changes due to Crohn's disease
| pronounce =
| field = Internal medicine
| symptoms = Diarrhoea; fever; abdominal pain, abdominal bloating; nutrient deficiencies
| complications = Dehydration, headache, electrolyte imbalance; sepsis (infectious enteritis); tissue dysplasia, cancer; [[small intestine bacterial overgrowth]]
| onset =
| duration =
| types =
| causes = Infectious; autoimmune; ischemic; radiation; toxic; [[idiopathic]]; other
| risks =
| diagnosis =
| differential =
| prevention =
| treatment =
| medication =
| prognosis =
| frequency =
| deaths =
}}
'''Enteritis''' is [[inflammation]] of the [[small intestine]]. It is most commonly caused by food or drink contaminated with [[pathogen]]ic microbes,<ref name=medline>Dugdale, David C., IIII, and George F Longretch [https://www.nlm.nih.gov/MEDLINEPLUS/ency/article/001149.htm "Enteritis"]. [[MedlinePlus]] Medical Encyclopedia, 18 October 2008. Accessed 24 August 2009.</ref> such as ''[[Serratia]]'', but may have other causes such as [[Nonsteroidal anti-inflammatory drug|NSAIDs]], [[radiation therapy]] as well as [[Autoimmune disease|autoimmune conditions]] like [[coeliac disease]]. Symptoms may include abdominal pain, cramping, [[diarrhoea]], [[dehydration]], and [[fever]].<ref name=medline/> Related diseases of the [[gastrointestinal system|gastrointestinal (GI) system]] (including [[gastritis]], [[gastroenteritis]], [[colitis]], and [[enterocolitis]]) may involve inflammation of the stomach and large intestine.

[[Duodenitis]], jejunitis, and [[ileitis]] are subtypes of enteritis which are localised to a specific part of the small intestine. Inflammation of both the stomach and small intestine is referred to as [[gastroenteritis]].<ref>{{cite web |url=https://www.lecturio.com/concepts/gastroenteritis/| title=Gastroenteritis
|website=The Lecturio Medical Concept Library |access-date= 23 July 2021}}</ref>

== Signs and symptoms ==
Signs and symptoms of enteritis are highly variable and vary based on the specific cause and other factors such as individual variance and stage of disease.
Symptoms may include [[abdominal pain]], [[cramp]]ing, [[diarrhea]],<ref>{{Cite web |title=Enteritis: MedlinePlus Medical Encyclopedia |url=https://medlineplus.gov/ency/article/001149.htm |access-date=2022-11-18 |website=medlineplus.gov |language=en}}</ref> [[dehydration]], [[fever]], [[nausea]], [[vomiting]], and [[weight loss]].<ref>{{cite web |url=https://www.healthgrades.com/right-care/digestive-health/enteritis| title=Enteritis
|website=HealthGrades | date=13 November 2019
|access-date= 23 July 2021}}</ref>

== Causes ==

=== Immune mediated ===
[[Crohn's disease]] – also known as regional enteritis, it can occur along any surface of the gastrointestinal tract. The most common location for Crohn's disease to manifest, with or without the involvement of the [[Large intestine|colon]] or other parts of the GI tract, is in the terminal [[ileum]] (the final segment of the small intestine).<ref name=":7">{{Cite book |last1=Friedman |first1=Sonia |title=Harrison's Principles of Internal Medicine |last2=Blumberg |first2=Richard S. |publisher=McGraw Hill |year=2022 |isbn=978-1264268504 |edition=21st |location=New York |language=English |chapter=Chapter 326: Inflammatory Bowel Disease}}</ref> In 40% of cases, it is limited to the small intestine.<ref name=":1" />

=== Autoimmune ===
[[Coeliac disease]] – caused by an [[autoimmune]] reaction to gluten by genetically predisposed individuals.<ref name=":1" />

[[Eosinophilic gastroenteritis]], also known as eosinophilic enteropathy or eosinophilic enteritis<ref name=":8">{{Cite journal |last1=Pineton de Chambrun |first1=Guillaume |last2=Dufour |first2=Gaspard |last3=Tassy |first3=Barbara |last4=Rivière |first4=Benjamin |last5=Bouta |first5=Najima |last6=Bismuth |first6=Michael |last7=Panaro |first7=Fabrizio |last8=Funakoshi |first8=Natalie |last9=Ramos |first9=Jeanne |last10=Valats |first10=Jean-Christophe |last11=Blanc |first11=Pierre |date=2018-07-02 |title=Diagnosis, Natural History and Treatment of Eosinophilic Enteritis: a Review |url=https://doi.org/10.1007/s11894-018-0645-6 |journal=Current Gastroenterology Reports |language=en |volume=20 |issue=8 |pages=37 |doi=10.1007/s11894-018-0645-6 |pmid=29968127 |s2cid=49648502 |issn=1534-312X|url-access=subscription }}</ref> – a rare and [[heterogeneous condition]] where [[eosinophil]]s build up in the gastrointestinal tract and blood vessels, leading to polyp formation, necrosis, inflammation and ulcers.<ref>{{Cite journal|last1=Fleischer|first1=David M.|last2=Atkins|first2=Dan|date=2009-02-01|title=Evaluation of the patient with suspected eosinophilic gastrointestinal disease|pmid=19141341|journal=Immunology and Allergy Clinics of North America|volume=29|issue=1|pages=53–63, ix|doi=10.1016/j.iac.2008.09.002|issn=1557-8607}}</ref> It is most commonly seen in patients with a history of [[atopy]], however is overall relatively uncommon.<ref name=":2">{{Cite journal|last1=Mori|first1=Amit|last2=Enweluzo|first2=Chijioke|last3=Grier|first3=David|last4=Badireddy|first4=Madhu|date=2013-05-01|title=Eosinophilic gastroenteritis: review of a rare and treatable disease of the gastrointestinal tract|pmid=23904840|journal=Case Reports in Gastroenterology|volume=7|issue=2|pages=293–298|doi=10.1159/000354147|issn=1662-0631|pmc=3728613}}</ref>

=== Infectious enteritis ===
In Germany, 90% of cases of infectious enteritis are caused by four pathogens, [[Norovirus]], ''[[Rotavirus]]'', ''[[Campylobacter]]'', and ''[[Salmonella]]''.<ref>{{Cite journal|last1=Epple|first1=H.-J.|last2=Zeitz|first2=M.|s2cid=24574799|date=2011-09-01|title=[Infectious enteritis]|journal=Der Internist|volume=52|issue=9|pages=1038, 1040–1044, 1046|doi=10.1007/s00108-011-2862-z|issn=1432-1289|pmid=21847579}}</ref> Other common causes of infectious enteritis include bacteria such as ''[[Shigella]]'' and ''[[Escherichia coli|E. coli]],'' as well as viruses such as adenovirus, astrovirus, and calicivirus. Other less common pathogens include ''[[Bacillus cereus]]'', ''[[Clostridium perfringens]]'', ''[[Clostridioides difficile]]'', and ''[[Staphylococcus aureus]]''.<ref name=":3">{{Cite book|url=https://books.google.com/books?id=aVmRWrknaWgC|title=Textbook of Therapeutics: Drug and Disease Management|last1=Helms|first1=Richard A.|last2=Quan|first2=David J.|date=2006-01-01|publisher=Lippincott Williams & Wilkins|isbn=9780781757348}}</ref>

''[[Campylobacter jejuni]]''  is one of the most common sources of infectious enteritis, and the most common bacterial pathogen found in two-year-old and smaller children with diarrhoea.<ref name=":4">{{Cite journal|last1=Coker|first1=Akitoye O.|last2=Isokpehi|first2=Raphael D.|last3=Thomas|first3=Bolaji N.|last4=Amisu|first4=Kehinde O.|last5=Obi|first5=C. Larry|date=2016-10-14|title=Human Campylobacteriosis in Developing Countries1|pmc=2732465|journal=Emerging Infectious Diseases|volume=8|issue=3|pages=237–243|doi=10.3201/eid0803.010233|issn=1080-6040|pmid=11927019}}</ref> It has been linked to consumption of contaminated water and food, most commonly poultry and milk.<ref>{{Cite journal|last1=Colles|first1=F. M.|last2=McCarthy|first2=N. D.|last3=Howe|first3=J. C.|last4=Devereux|first4=C. L.|last5=Gosler|first5=A. G.|last6=Maiden|first6=M. C. J.|date=2009-01-01|title=Dynamics of Campylobacter colonization of a natural host, Sturnus vulgaris (European Starling)|journal=Environmental Microbiology|volume=11|issue=1|pages=258–267|doi=10.1111/j.1462-2920.2008.01773.x|issn=1462-2920|pmid=18826435|pmc=2702492|bibcode=2009EnvMi..11..258C }}</ref><ref>{{Cite journal|last=Peterson|first=Michael C.|date=2003-05-01|title=Campylobacter jejuni enteritis associated with consumption of raw milk|pmid=12762121|journal=Journal of Environmental Health|volume=65|issue=9|pages=20–21, 24, 26|issn=0022-0892}}</ref> The disease tends to be less severe in developing countries, due to the constant exposure which people have with the antigen in the environment, leading to early development of antibodies.<ref name=":4" />

Rotavirus is responsible for infecting 140&nbsp;million people and causing 1&nbsp;million deaths each year, mostly in children younger than five years.<ref name=":1" /><ref name=":5">{{Cite journal|last=Ramig|first=Robert F.|date=2004-10-01|title=Pathogenesis of intestinal and systemic rotavirus infection|pmid=15367586|journal=Journal of Virology|volume=78|issue=19|pages=10213–10220|doi=10.1128/JVI.78.19.10213-10220.2004|issn=0022-538X|pmc=516399}}</ref> This makes it the most common cause of severe childhood diarrhoea and diarrhea-related deaths in the world.<ref name=":1" /> It selectively targets mature enterocytes in the small intestine, causing malabsorption, as well as inducing secretion of water. It has also been observed to cause villus ischemia, and increase intestinal motility.<ref name=":5" /> The net result of these changes is induced diarrhoea.<ref name=":5" />

[[Clostridial necrotizing enteritis|Enteritis necroticans]] is an often fatal illness, caused by [[β-toxin]] of ''Clostridium perfringens''.<ref name=":6">{{Cite journal|last1=Petrillo|first1=T. M.|last2=Beck-Sagué|first2=C. M.|last3=Songer|first3=J. G.|last4=Abramowsky|first4=C.|last5=Fortenberry|first5=J. D.|last6=Meacham|first6=L.|last7=Dean|first7=A. G.|last8=Lee|first8=H.|last9=Bueschel|first9=D. M.|date=2000-04-27|title=Enteritis necroticans (pigbel) in a diabetic child|pmid=10781621|journal=The New England Journal of Medicine|volume=342|issue=17|pages=1250–1253|doi=10.1056/NEJM200004273421704|issn=0028-4793|doi-access=free}}</ref> This causes inflammation and segments of necrosis throughout the gastrointestinal tract. It is most common in [[Developing country|developing countries]]; however, it has also been documented in [[Aftermath of World War II|post-World War II]] [[Germany]].<ref name=":6" /> Risk factors for enteritis necroticans include decreased trypsin activity, which prevent intestinal degradation of the toxin, and reduced intestinal motility, which increases likelihood of toxin accumulation.<ref name=":6" />

=== Vascular disease ===
Ischemic enteritis is uncommon compared to ischemic colitis due to the highly vascularised nature of the small intestine,<ref name=":0">{{Cite journal|last1=Koshikawa|first1=Yorimitsu|last2=Nakase|first2=Hiroshi|last3=Matsuura|first3=Minoru|last4=Yoshino|first4=Takuya|last5=Honzawa|first5=Yusuke|last6=Minami|first6=Naoki|last7=Yamada|first7=Satoshi|last8=Yasuhara|first8=Yumiko|last9=Fujii|first9=Shigehiko|date=2016-10-12|title=Ischemic enteritis with intestinal stenosis|pmc=4754528|journal=Intestinal Research|volume=14|issue=1|pages=89–95|doi=10.5217/ir.2016.14.1.89|issn=1598-9100|pmid=26884740}}</ref> allowing for sufficient blood flow in most situations. It develops due to [[Shock (circulatory)|circulatory shock]] of mesenteric vessels in the absence of major vessel occlusion, often associated with an underlying condition such as hypertension, arrhythmia, or diabetes.<ref name=":0" /> Thus, it has been considered to be associated with atherosclerosis.<ref>{{Cite journal|last1=Takeuchi|first1=Nobuhiro|last2=Naba|first2=Kazuyoshi|date=2013-01-01|title=Small intestinal obstruction resulting from ischemic enteritis: a case report|pmc=3751282|journal=Clinical Journal of Gastroenterology|volume=6|issue=4|pages=281–286|doi=10.1007/s12328-013-0393-y|issn=1865-7257|pmid=23990850}}</ref> Surgical treatment is usually required due to the likelihood of stenosis or complete occlusion of the small intestine.<ref name=":0" /> Ischemic damage can range from [[Mucous membrane|mucosal]] [[infarction]], which is limited only to the mucosa; mural infarction of the mucosa and underlying [[submucosa]]; to transmural infarction of the full thickness of the gastrointestinal wall. Mucosal and mural infarcts in and of themselves may not be fatal, however may progress further to a transmural infarct.<ref name=":1">{{Cite book|title=Robbins Basic Pathology|last1=Kumar|first1=Vinay|last2=Abbas|first2=Abul K.|last3=Aster|first3=Jon C.|last4=Robbins|first4=Stanley L.|publisher=Elsevier/Saunders|year=2012|isbn=9781437717815|location=Philadelphia, PA|edition=9th}}</ref> This has the potential for perforation of the wall, leading to [[peritonitis]].{{citation needed|date=June 2022}}

=== Radiation enteritis ===
{{Main|Radiation enteropathy}}

Inflammation of the gastrointestinal tract is common after treatment with radiation therapy to the abdomen or pelvis.<ref name = radiation>{{Cite journal|last1=Hauer-Jensen|first1=Martin|last2=Denham|first2=James W.|last3=Andreyev|first3=H. Jervoise N.|date=2016-10-14 |title= Radiation Enteropathy – Pathogenesis, Treatment, and Prevention|pmc=4346191|journal=Nature Reviews. Gastroenterology & Hepatology|volume=11 |issue= 8|pages=470–479|doi=10.1038/nrgastro.2014.46|issn=1759-5045|pmid=24686268}}</ref> It is classified as early if it manifests within the first three months, and delayed if it manifests three months after treatment. Early radiation enteritis is caused by cell death of the [[Intestinal gland|crypt epithelium]] and subsequent mucosal inflammation, however usually subsides after the course of radiation therapy is completed. Delayed radiation enteritis is a chronic disease which has a complex pathogenesis involving changes in the majority of the intestinal wall.<ref name = radiation/><ref>{{cite journal |vauthors=Stacey R, Green JT |title=Radiation-induced small bowel disease: latest developments and clinical guidance |journal=Ther Adv Chronic Dis |volume=5 |issue=1 |pages=15–29 |year=2014 |pmid=24381725 |pmc=3871275 |doi=10.1177/2040622313510730 }}</ref>

== Diagnosis ==
Diagnosis may be simple in cases where the patient's signs and symptoms are [[Idiopathic disease|idiopathic]]. However, this is generally not the case, considering that many pathogens which cause enteritis may exhibit similar symptoms, especially early in the disease. In particular, ''Campylobacter'', ''Shigella'', ''Salmonella'' and many other bacteria induce acute self-limited colitis, an inflammation of the lining of the colon which appears similar under the microscope.<ref name=":1" />

A medical history, physical examination and tests such as blood counts, stool cultures, CT scans, MRIs, PCRs, colonoscopies and upper endoscopies may be used in order to perform a differential diagnosis.<ref name=":2" /><ref name=":3" /><ref name=":6" /><ref>{{Cite journal|last1=Gregg|first1=Clark R.|last2=Nassar|first2=Naiel N.|s2cid=27491100|date=1999-04-01|title=Infectious Enteritis|pmid=11096582 |journal=Current Treatment Options in Gastroenterology|volume=2|issue=2|pages=119–126|issn=1092-8472|doi=10.1007/s11938-999-0039-9}}</ref> A biopsy may be required to obtain a sample for histopathology.{{citation needed|date=October 2022}}

== Treatment ==
{{Expand section|This section lacks substantial information about the treatment of most forms of enteritis. Treatment of enteritis is often much more involved than this section currently indicates.|date=January 2024}}
Mild cases usually do not require treatment and will go away after a few days in healthy people.<ref name=":1" /><ref name=":3" /> In cases where symptoms persist or when it is more severe, specific treatments based on the initial cause may be required.{{citation needed|date=June 2022}}

In cases where persistent diarrhea is present, replenishing lost fluids by mouth is recommended, and for severe diarrhea intravenous hydration therapy and antibiotics may be required.<ref>{{Cite book|url=https://books.google.com/books?id=zEZOqB6r9hwC|title=Sleisenger and Fordtran's Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management, Expert Consult Premium Edition - Enhanced Online Features|last1=Feldman|first1=Mark|last2=Friedman|first2=Lawrence S.|last3=Brandt|first3=Lawrence J.|date=2010-05-03|publisher=Elsevier Health Sciences|isbn=978-1437727678}}</ref> A simple [[oral rehydration therapy]] (ORS) can be made by dissolving one teaspoon of salt, eight teaspoons of sugar and the juice of an orange into one litre of clean water.<ref>{{Cite book|url=https://books.google.com/books?id=pZ9fpHtvOGYC|title=Communicable Disease Epidemiology and Control: A Global Perspective|last=Webber|first=Roger|date=2009-01-01|publisher=CABI|isbn=9781845935054}}</ref> Studies have shown the efficacy of antibiotics in reducing the duration of the symptoms of infectious enteritis of bacterial origin, however antibiotic treatments are usually not required due to the self-limiting duration of infectious enteritis.<ref name=":3" />

=== Autoimmune ===
{{See also|Management of Crohn's disease}}
Autoimmune causes of enteritis such as [[Crohn's disease]] require significant chronic [[Management of Crohn's disease|treatment]] to avoid [[Malnutrition|nutritional deficiencies]], [[Small intestine cancer|cancer]], [[Small intestinal bacterial overgrowth|bacterial overgrowth]], and other complications.<ref name=":7" /> Some patients with mild forms of the disease may not need treatment, but a majority of people with Crohn's disease require [[glucocorticoid]] medications.<ref>{{Cite web |last1=Regueiro |first1=Miguel |last2=Al Hashash |first2=Jana |date=8 August 2022 |title=Overview of the medical management of mild (low risk) Crohn disease in adults |url=https://www.uptodate.com/contents/overview-of-the-medical-management-of-mild-low-risk-crohn-disease-in-adults |access-date=2024-01-03 |website=UpToDate |publisher=Wolters Kluwer}}</ref> 

For treating [[eosinophilic gastroenteritis]], the main treatment is usually a [[corticosteroid]] medication, as these have been shown to have good [[efficacy]] in managing eosinophilic gastroenteritis. Other treatments include modifying diets to avoid food allergies, [[azathioprine]] and antibodies, including [[mepolizumab]], [[omalizumab]], [[infliximab]], and [[adalimumab]].<ref name=":8" />

==Etymology==
The word ''enteritis'' ({{IPAc-en|ˌ|ɛ|n|t|ə|ˈ|r|ai|t|ᵻ|s}}) uses [[classical compound|combining forms]] of ''[[wikt:entero-#Prefix|entero-]]'' and ''[[wikt:-itis#Suffix|-itis]]'', both [[Neo-Latin]] from [[Greek Language|Greek]], respectively from ἑντερον (''enteron'', [[small intestine]]) and -ιτις (''-itis'', [[inflammation]]).{{citation needed|date=July 2020}}

==See also==
* [[Enteropathy]]
* [[Staphylococcal enteritis]]

==References==
{{Reflist}}

== External links ==
*{{commonscatinline}}
{{Medical resources
|  DiseasesDB     =
|  ICD10          = {{ICD10|A|02||a|00}}-{{ICD10|A|09||a|00}}, {{ICD10|K|50||k|50}}-{{ICD10|K|55||k|55}}
|  ICD9           = {{ICD9|005}}, {{ICD9|008}}, {{ICD9|009}}, {{ICD9|555}}-{{ICD9|558}}
|  ICDO           =
|  OMIM           =
|  MedlinePlus    = 001149
|  eMedicineSubj  =
|  eMedicineTopic =
|  MeshID         = D004751
}}

{{Gastroenterology}}
{{Authority control}}

[[Category:Inflammations]]
[[Category:Intestinal infectious diseases]]