Inflammatory bowel disease: Difference between revisions

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{{Inflammatory bowel disease}}
{{Inflammatory bowel disease}}
{{CMG}} ; {{AE}} {{ADG}}
{{CMG}} ; {{AE}} {{ADG}}<br>
{{SK}}
{{SK}} IBD ;
==Overview==
==Overview==
Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract that represents 2 distinctive disorders, Crohn disease and ulcerative colitis. Both disorders are characterized by unpredictable exacerbations and remissions. The most common time of onset of IBD is during the preadolescent/adolescent era and young adulthood. IBD may also be classified according to age at onset pediatric onset (<17 yr), early onset (<10 yr), very early onset (<6 yr), infant/toddler onset (0-2 yr), and neonatal onset IBD. Genetic and environmental factors are involved in the pathogenesis of IBD. A dysregulated immune response to environmental factors in a genetically susceptible host involving activation of cytokines, triggering a cascade of reactions results in bowel inflammation. The prevalence of Crohn disease in the United States is much lower for Hispanics and Asians than for whites and blacks. It is usually possible to distinguish between ulcerative colitis and Crohn disease by the clinical presentation and radiologic, endoscopic, and histopathologic findings. Common symptoms of inflammatory bowel disease include persistent diarrhea, abdominal pain, rectal bleeding/bloody stools, weight loss and fatigue. IBD is diagnosed using a combination of endoscopy for Crohn’s disease or colonoscopy for ulcerative colitis and imaging studies, such as contrast radiography, magnetic resonance imaging (MRI), or computed tomography (CT).
Inflammatory bowel disease (IBD) is a chronic [[inflammatory disease]] of the [[gastrointestinal tract]] that represents 2 distinctive disorders, Crohn's disease and [[ulcerative colitis]]. Both disorders are characterized by unpredictable exacerbations and [[Remission|remissions]]. [[Genetic]] and environmental factors are believed to play a key role in the [[pathogenesis]] of IBD. A dysregulated [[immune response]] to environmental factors in a genetically susceptible [[Hosts|host]] results in activation of [[cytokines]], triggering a cascade of reactions ultimately bowel [[inflammation]]. Common symptoms of inflammatory bowel disease include persistent [[diarrhea]], [[abdominal pain]], [[rectal bleeding]]/[[bloody stools]], [[weight loss]] and [[fatigue]]. IBD can be diagnosed using a combination of [[endoscopy]] for [[Crohn's disease|Crohn’s disease]] or [[colonoscopy]] for [[ulcerative colitis]] and imaging studies, such as contrast radiography, magnetic resonance imaging, or computed tomography. The goal of medical therapy is to induce [[Remission (medicine)|remission]] initially with medications, followed by the administration of [[Maintenance dose|maintenance]] medications to prevent a [[relapse]] of the disease. [[Sulfasalazine]] along with [[steroids]] are the main stay of treatment for IBD.  [[Immunosuppressive agents]] such as [[infliximab]] or 6-[[mercaptopurine]] and [[azathioprine]] are recommended alternatives to [[steroids]].


==Causes==
==Causes==
While the causes of inflammatory bowel disease is unknown, several possibly interrelated studies have been suggested following causes:
=== Common causes ===
==== Genetic factors ====
* [[Mutation|Mutations]] in the [[NOD2|CARD15]] gene (also known as the NOD2 [[gene]]) are associated with Crohn's disease.
* Mutations of the transporter proteins such as OCTN1 and OCTN2 and scaffolding proteins such as the MAGUK family are believed to cause ulcerative colitis.
==== Environmental factors ====
* Alterations in normal bacterial flora of the intestinal tract is responsible for Crohn's disease.
* [[Tobacco smoking|Smoking]]: Unlike Crohn's disease, ulcerative colitis has a lesser [[prevalence]] in smokers than non-smokers.
* Use of [[NSAID|NSAIDs]]
* Stress
* Red meat consumption
==== Rare causes ====
* [[Hemolytic-uremic syndrome|Hemolytic uremic syndrome]]
* [[Connective tissue disease]]
* [[Vasculitis]]
* [[Radiation therapy]] to the [[prostate]] or [[Pelvis|pelvic area]]
* Chemical or physical trauma to anorectal area
* [[Amyloidosis]]
* [[Behçet's disease|Behçet syndrome]]
* [[Chronic lymphocytic leukemia]]
* [[Lymphoma]]
* [[Proctocolitis|Lipid proctocolitis]]
* [[Tuberculosis]]
* [[Syphilis]]
* Infection with ''[[Entamoeba histolytica]]'' or ''[[Giardia lamblia]]'', most often seen in patients with [[AIDS|acquired immune deficiency syndrome]].
* Infection with ''[[C difficile]]''
==Classification==
==Classification==
Inflammatory bowel disease can be classified into Crohn's disease and ulcerative colitis.
{{familytree/start}}
{{familytree | | | | | | | | | | | | | | | | | | | | | | A01 | | | | | |A01=Inflammatory Bowel Disease}}
{{familytree | | | | | | | | | | | | | | | | | | | | | | |!| | | | | | | | }}
{{familytree | | | | | | | | | | | | | |,|-|-|-|-|-|-|-|-|^|-|-|-|-|-|-|.| | }}
{{familytree | | | | | | | | | | | | | B01 | | | | | | | | | | | | | | B02 |B01=Crohn's Disease|B02=Ulcerative colitis}}
{{familytree | | | | | | | | | | | | | |!| | | | | | | | | | | | | | | |!| }}
{{familytree | | | | | | | |,|-|-|-|-|-|^|-|-|-|-|-|.| | | | | | | | | |!|}}
{{familytree | | | | | | | Z01 | | | | | | | | | | Z02 | | | | | | | | |!| |Z01=Based on Region involved|Z02=Based on Severity}}
{{familytree | | | |,|-|-|-|+|-|-|-|.| | | |,|-|-|-|+|-|-|-|.| | | | | |!| | }}
{{familytree | | | C01 | | C02 | | C03 | | C04 | | C05 | | C06 | | | | |!| |C01=Ileocolic Crohn's disease|C02=Crohn's ileitis|C03=Crohn's colitis|C04=Stricturing disease|C05=Penetrating disease|C06=Inflammatory disease}}
{{familytree | | | | | | | | | | | | | | | | | | | | | | | |,|-|-|-|-|-|^|-|-|-|.| | }}
{{familytree | | | | | | | | | | | | | | | | | | | | | | | Z01 | | | | | | | | Z02 | |Z01=Based on Region involved|Z02=Based on Severity}}
{{familytree | | | | | | | | | | | | | | | | | | | |,|-|-|-|^|-|.| | | |,|-|-|-|+|-|-|-|v|-|-|-|.| }}
{{familytree | | | | | | | | | | | | | | | | | | | C01 | | | | C02 | | C03 | | C04 | | C05 | | C06 | C01=Distal UC|C02=Proximal UC|C03=Mild|C04=Moderate|C05=Severe|C06=Flumiant|}}
{{familytree/end}}
==Differential diagnosis==
==Differential diagnosis==
Inflammatory bowel disease must be differentiated from other diseases that  present with [[abdominal pain]], [[fever]] and [[diarrhea]] which include [[appendicitis]], [[diverticulitis]], [[Whipple's disease]], [[mesenteric ischemia]], [[Tropical sprue]], [[hepatitis]] and [[spontaneous bacterial peritonitis]].
{| align="center"
|-
|
{| style="border: 0px; font-size: 90%; margin: 3px;" align="center"
! rowspan="3" style="background:#4479BA; color: #FFFFFF;" align="center" |Disease
| colspan="13" rowspan="1" style="background:#4479BA; color: #FFFFFF;" align="center" |'''Clinical manifestations'''
! colspan="2" rowspan="2" style="background:#4479BA; color: #FFFFFF;" align="center" |Diagnosis
! rowspan="3" style="background:#4479BA; color: #FFFFFF;" align="center" |Comments
|-
| colspan="9" rowspan="1" style="background:#4479BA; color: #FFFFFF;" align="center" |'''Symptoms'''
! colspan="4" rowspan="1" style="background:#4479BA; color: #FFFFFF;" align="center" | Signs
|-
! style="background:#4479BA; color: #FFFFFF;" align="center" |Abdominal Pain
! colspan="1" rowspan="1" style="background:#4479BA; color: #FFFFFF;" align="center" | Fever
! style="background:#4479BA; color: #FFFFFF;" align="center" |Rigors and chills
! style="background:#4479BA; color: #FFFFFF;" align="center" |Nausea or vomiting
! style="background:#4479BA; color: #FFFFFF;" align="center" |Jaundice
! style="background:#4479BA; color: #FFFFFF;" align="center" |Constipation
! style="background:#4479BA; color: #FFFFFF;" align="center" |Diarrhea
! style="background:#4479BA; color: #FFFFFF;" align="center" |Weight loss
! style="background:#4479BA; color: #FFFFFF;" align="center" |GI bleeding
! style="background:#4479BA; color: #FFFFFF;" align="center" |Hypo-
tension
! colspan="1" rowspan="1" style="background:#4479BA; color: #FFFFFF;" align="center" | Guarding
! style="background:#4479BA; color: #FFFFFF;" align="center" |Rebound Tenderness
! style="background:#4479BA; color: #FFFFFF;" align="center" |Bowel sounds
! colspan="1" rowspan="1" style="background:#4479BA; color: #FFFFFF;" align="center" | Lab Findings
! style="background:#4479BA; color: #FFFFFF;" align="center" |Imaging
|-
| style="padding: 5px 5px; background: #DCDCDC;" align="center" |[[Inflammatory bowel disease|'''Inflammatory bowel disease''']]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |Diffuse
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |Normal or hyperactive
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* [[Anti-neutrophil cytoplasmic antibody]] ([[P-ANCA]]) in [[Ulcerative colitis]]
* [[Anti saccharomyces cerevisiae antibodies]] (ASCA) in [[Crohn's disease]]
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* [[String sign]] on [[abdominal x-ray]] in [[Crohn's disease]]
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
Extra intestinal findings:
* [[Uveitis]]
* [[Arthritis]]
|-
| colspan="1" rowspan="1" style="padding: 5px 5px; background: #DCDCDC;" align="center" |[[Acute appendicitis|'''Acute appendicitis''']]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |Starts in [[epigastrium]], migrates to RLQ
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | Positive in pyogenic appendicitis
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |−
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |−
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | Positive in perforated appendicitis
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |Hypoactive
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* [[Leukocytosis]]
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* Ct scan
* Ultrasound
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* Positive Rovsing sign
* Positive Obturator sign
* Positive Iliopsoas sign
|-
| colspan="1" rowspan="1" style="padding: 5px 5px; background: #DCDCDC;" align="center" |[[Diverticulitis|'''Acute diverticulitis''']]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |LLQ
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |−
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | Positive in perforated diverticulitis
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |Hypoactive
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* [[Leukocytosis]]
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* CT scan 
* Ultrasound
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* History of [[constipation]]
|-
| style="padding: 5px 5px; background: #DCDCDC;" align="center" |[[Whipple's disease|'''Whipple's disease''']]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |Diffuse
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |N
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* [[Thrombocytopenia]]
* [[Hypoalbuminemia]]
* [[Small intestinal]] [[biopsy]] for [[Tropheryma whipplei]]
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |[[Whipple's disease other diagnostic studies|Endoscopy]] is used to confirm diagnosis.
Images used to find complications
*[[Whipple's disease x ray|Chest and joint x-ray]]
*[[Whipple's disease CT|CT]]
*[[Whipple's disease MRI|MRI]]
*[[Whipple's disease ultrasound|Echocardiography]]
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |Extra intestinal findings:
* [[Uveitis]]
* [[Endocarditis]]
* [[Encephalitis]]
* [[Dementia]]
* [[Hepatosplenomegaly]]
* [[Arthritis]]
* [[Ascites]]
|-
| style="padding: 5px 5px; background: #DCDCDC;" align="center" |[[Toxic megacolon|'''Toxic megacolon''']]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |Diffuse
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |Hypoactive
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* [[Anemia]]
*[[Leukocytosis]] especially in patients with [[Clostridium difficile infection|''Clostridium difficile'' infection]]
*[[Hypoalbuminemia]]
*[[Metabolic alkalosis]] associated with a poor [[prognosis]]
*[[Metabolic acidosis]] secondary to [[ischemic colitis]]
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |CT and [[Ultrasound]] shows:
*Loss of colonic haustration
*Hypoechoic and thickened bowel walls with irregular internal margins in the [[sigmoid]] and descending colon
*Prominent dilation of the transverse colon (>6 cm)
* Insignificant dilation of ileal bowel loops (diameter >18 mm) with increased intraluminal gas and fluid
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
|-
| style="padding: 5px 5px; background: #DCDCDC;" align="center" |[[Tropical sprue|'''Tropical sprue''']]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |Diffuse
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |N
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* Fat soluble vitamin deficiency
* [[Hypoalbuminemia]]
* Fecal stool test
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |Barium studies:
* Dilation and edema of mucosal folds
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* [[Steatorrhea]]- 10-40 g/day (Normal=5 g/day)
|-
| style="padding: 5px 5px; background: #DCDCDC;" align="center" |[[Infective colitis|'''Infective colitis''']]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |Diffuse
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | Positive in fulminant colitis
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |Hyperactive
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* [[Stool culture]] and studies
* Shiga toxin in bloody diarrhea
* [[PCR]]
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |CT scan
* Bowel wall thickening
* Edema
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
|-
| style="padding: 5px 5px; background: #DCDCDC;" align="center" |[[Hepatitis|'''Viral hepatitis''']]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |[[RUQ]]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | Positive in Hep A and E
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | Positive in fulminant hepatitis
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | Positive in acute
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |N
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* Abnormal LFTs
* Viral serology
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* US
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* Hep A and E have fecal-oral route of transmission
* Hep B and C transmits via blood transfusion and sexual contact.
|-
| style="padding: 5px 5px; background: #DCDCDC;" align="center" |[[Liver abscess|'''Liver abscess''']]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |RUQ
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |Normal or hypoactive
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* CBC
* Blood cultures
* Abnormal [[Liver function test|liver function tests]]
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* US
* CT
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
|-
| colspan="1" rowspan="1" style="padding: 5px 5px; background: #DCDCDC;" align="center" |[[Spontaneous bacterial peritonitis|'''Spontaneous bacterial peritonitis''']]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |Diffuse
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | Positive in cirrhotic patients
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |Hypoactive
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* Ascitic fluid [[PMN]]>250 cells/mm<small>³</small>
* Culture: Positive for single organism
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* Ultrasound for evaluation of liver cirrhosis
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
|-
| style="padding: 5px 5px; background: #DCDCDC;" align="center" |[[Mesenteric ischemia|'''Mesenteric ischemia''']]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |Periumbilical
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |Positive if bowel becomes gangrenous
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | Positive if bowel becomes gangrenous
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | Positive if bowel becomes gangrenous
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |Hyperactive to absent
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* [[Leukocytosis]] and [[lactic acidosis]]
* [[Amylase]] levels
* [[D-dimer]]
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |CT angiography
* SMA or SMV thrombosis
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* Also known as abdominal angina  that worsens with eating
|-
| style="padding: 5px 5px; background: #DCDCDC;" align="center" |[[Ischemic colitis|'''Acute ischemic colitis''']]
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | Diffuse
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | ±
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | −
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" | +
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="center" |<nowiki>+</nowiki>
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |Hyperactive then absent
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |
* [[Leukocytosis]]
| style="padding: 5px 5px; background: #F5F5F5;" align="left" |[[Abdominal x-ray]]
* Distension and pneumatosis
CT scan
* Double halo appearance, thumbprinting
* Thickening of bowel
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* May lead to shock
|-
|}
|}
<span style="font-size:85%">'''Abbreviations:'''
'''[[RUQ]]'''= Right upper quadrant of the abdomen, '''LUQ'''= Left upper quadrant, '''LLQ'''= Left lower quadrant, '''RLQ'''= Right lower quadrant, '''LFT'''= Liver function test, SIRS= [[Systemic inflammatory response syndrome]], '''[[ERCP]]'''= [[Endoscopic retrograde cholangiopancreatography]], '''IV'''= Intravenous, '''N'''= Normal, '''AMA'''= Anti mitochondrial antibodies, '''[[LDH]]'''= [[Lactate dehydrogenase]], '''GI'''= Gastrointestinal, '''CXR'''= Chest X ray, '''IgA'''= [[Immunoglobulin A]], '''IgG'''= [[Immunoglobulin G]], '''IgM'''= [[Immunoglobulin M]], '''CT'''= [[Computed tomography]], '''[[PMN]]'''= Polymorphonuclear cells, '''[[ESR]]'''= [[Erythrocyte sedimentation rate]], '''[[CRP]]'''= [[C-reactive protein]], TS= [[Transferrin saturation]], SF= Serum [[Ferritin]], SMA= [[Superior mesenteric artery]], SMV= [[Superior mesenteric vein]], ECG= [[Electrocardiogram]]</span>

Latest revision as of 20:34, 8 January 2018

Inflammatory Bowel Disease Main page

Patient Information

Overview

Causes

Classification

Crohn's disease
Ulcerative colitis

Differential Diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] ; Associate Editor(s)-in-Chief: Aditya Ganti M.B.B.S. [2]
Synonyms and keywords: IBD ;

Overview

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract that represents 2 distinctive disorders, Crohn's disease and ulcerative colitis. Both disorders are characterized by unpredictable exacerbations and remissions. Genetic and environmental factors are believed to play a key role in the pathogenesis of IBD. A dysregulated immune response to environmental factors in a genetically susceptible host results in activation of cytokines, triggering a cascade of reactions ultimately bowel inflammation. Common symptoms of inflammatory bowel disease include persistent diarrhea, abdominal pain, rectal bleeding/bloody stools, weight loss and fatigue. IBD can be diagnosed using a combination of endoscopy for Crohn’s disease or colonoscopy for ulcerative colitis and imaging studies, such as contrast radiography, magnetic resonance imaging, or computed tomography. The goal of medical therapy is to induce remission initially with medications, followed by the administration of maintenance medications to prevent a relapse of the disease. Sulfasalazine along with steroids are the main stay of treatment for IBD. Immunosuppressive agents such as infliximab or 6-mercaptopurine and azathioprine are recommended alternatives to steroids.

Causes

While the causes of inflammatory bowel disease is unknown, several possibly interrelated studies have been suggested following causes:

Common causes

Genetic factors

  • Mutations in the CARD15 gene (also known as the NOD2 gene) are associated with Crohn's disease.
  • Mutations of the transporter proteins such as OCTN1 and OCTN2 and scaffolding proteins such as the MAGUK family are believed to cause ulcerative colitis.

Environmental factors

  • Alterations in normal bacterial flora of the intestinal tract is responsible for Crohn's disease.
  • Smoking: Unlike Crohn's disease, ulcerative colitis has a lesser prevalence in smokers than non-smokers.
  • Use of NSAIDs
  • Stress
  • Red meat consumption

Rare causes

Classification

Inflammatory bowel disease can be classified into Crohn's disease and ulcerative colitis.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Inflammatory Bowel Disease
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Crohn's Disease
 
 
 
 
 
 
 
 
 
 
 
 
 
Ulcerative colitis
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Based on Region involved
 
 
 
 
 
 
 
 
 
Based on Severity
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Ileocolic Crohn's disease
 
Crohn's ileitis
 
Crohn's colitis
 
Stricturing disease
 
Penetrating disease
 
Inflammatory disease
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Based on Region involved
 
 
 
 
 
 
 
Based on Severity
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Distal UC
 
 
 
Proximal UC
 
Mild
 
Moderate
 
Severe
 
Flumiant

Differential diagnosis

Inflammatory bowel disease must be differentiated from other diseases that present with abdominal pain, fever and diarrhea which include appendicitis, diverticulitis, Whipple's disease, mesenteric ischemia, Tropical sprue, hepatitis and spontaneous bacterial peritonitis.

Disease Clinical manifestations Diagnosis Comments
Symptoms Signs
Abdominal Pain Fever Rigors and chills Nausea or vomiting Jaundice Constipation Diarrhea Weight loss GI bleeding Hypo-

tension

Guarding Rebound Tenderness Bowel sounds Lab Findings Imaging
Inflammatory bowel disease Diffuse ± ± + + + Normal or hyperactive

Extra intestinal findings:

Acute appendicitis Starts in epigastrium, migrates to RLQ + Positive in pyogenic appendicitis + ± Positive in perforated appendicitis + + Hypoactive
  • Ct scan
  • Ultrasound
  • Positive Rovsing sign
  • Positive Obturator sign
  • Positive Iliopsoas sign
Acute diverticulitis LLQ + ± + + ± + Positive in perforated diverticulitis + + Hypoactive
  • CT scan
  • Ultrasound
Whipple's disease Diffuse ± ± + + ± N Endoscopy is used to confirm diagnosis.

Images used to find complications

Extra intestinal findings:
Toxic megacolon Diffuse + + + ± + Hypoactive CT and Ultrasound shows:
  • Loss of colonic haustration
  • Hypoechoic and thickened bowel walls with irregular internal margins in the sigmoid and descending colon
  • Prominent dilation of the transverse colon (>6 cm)
  • Insignificant dilation of ileal bowel loops (diameter >18 mm) with increased intraluminal gas and fluid
Tropical sprue Diffuse + + + N Barium studies:
  • Dilation and edema of mucosal folds
Infective colitis Diffuse + ± + + Positive in fulminant colitis ± ± Hyperactive CT scan
  • Bowel wall thickening
  • Edema
Viral hepatitis RUQ + + + Positive in Hep A and E + Positive in fulminant hepatitis Positive in acute + N
  • Abnormal LFTs
  • Viral serology
  • US
  • Hep A and E have fecal-oral route of transmission
  • Hep B and C transmits via blood transfusion and sexual contact.
Liver abscess RUQ + + + + ± + + + ± Normal or hypoactive
  • US
  • CT
Spontaneous bacterial peritonitis Diffuse + Positive in cirrhotic patients + ± + + Hypoactive
  • Ascitic fluid PMN>250 cells/mm³
  • Culture: Positive for single organism
  • Ultrasound for evaluation of liver cirrhosis
Mesenteric ischemia Periumbilical Positive if bowel becomes gangrenous + + + + Positive if bowel becomes gangrenous Positive if bowel becomes gangrenous Hyperactive to absent CT angiography
  • SMA or SMV thrombosis
  • Also known as abdominal angina that worsens with eating
Acute ischemic colitis Diffuse + ± + + + + + + + Hyperactive then absent Abdominal x-ray
  • Distension and pneumatosis

CT scan

  • Double halo appearance, thumbprinting
  • Thickening of bowel
  • May lead to shock

Abbreviations: RUQ= Right upper quadrant of the abdomen, LUQ= Left upper quadrant, LLQ= Left lower quadrant, RLQ= Right lower quadrant, LFT= Liver function test, SIRS= Systemic inflammatory response syndrome, ERCP= Endoscopic retrograde cholangiopancreatography, IV= Intravenous, N= Normal, AMA= Anti mitochondrial antibodies, LDH= Lactate dehydrogenase, GI= Gastrointestinal, CXR= Chest X ray, IgA= Immunoglobulin A, IgG= Immunoglobulin G, IgM= Immunoglobulin M, CT= Computed tomography, PMN= Polymorphonuclear cells, ESR= Erythrocyte sedimentation rate, CRP= C-reactive protein, TS= Transferrin saturation, SF= Serum Ferritin, SMA= Superior mesenteric artery, SMV= Superior mesenteric vein, ECG= Electrocardiogram