Short bowel syndrome pathophysiology: Difference between revisions

Jump to navigation Jump to search
No edit summary
m (Bot: Removing from Primary care)
 
(30 intermediate revisions by 2 users not shown)
Line 5: Line 5:


==Overview==
==Overview==
The exact pathogenesis of [disease name] is not fully understood.
Short bowel syndrome occurrs as a result of [[bowel resection]] following various diseases of the gut such as [[Crohn's disease]], [[Cancer|malignancies]], [[ischemia]], and [[Physical trauma|trauma]]. Short bowel syndrome occurs when the length of the [[small intestine]] is less than 2 meters and requires [[Nutrition|nutritional]] therapy to prevent [[malnutrition]]. Post [[bowel resection]], adaptation might occur which includes structural, motility and functional changes in the remaining [[intestine]]. Changes usually start in the first 24 hours following [[bowel resection]] and last for about two years. [[Adaptation]] depends upon multiple factors including individual, [[Intestine|intestinal]] and [[Therapy|therapeutic]] measurements. Following [[bowel resection]], [[adaptation]] occurs in three phases including acute, adaptive, and maintenance phases. Successful [[adaptation]] depends on the length of remaining [[intestine]], portion of the resected [[intestine]], and early introduction of [[nutrition]] therapy. The term total [[Intestine|intestinal]] [[adaptation]] is used when the patient is weaned from [[Total parenteral nutrition|parenteral nutrition]]. The main reason for [[malabsorption]] following [[bowel resection]] is reduced [[Absorptive state|absorptive]] capacity of the [[small intestine]] due to loss of surface area. On [[Gross examination|gross]] and [[microscopic]] examination, the resected [[Intestine|bowel]] segment may show the underlying causes including [[Crohn's disease]], [[Cancer|malignancies]] or [[ischemia]].
 
OR
 
It is thought that [disease name] is the result of / is mediated by / is produced by / is caused by either [hypothesis 1], [hypothesis 2], or [hypothesis 3].
 
OR
 
[Pathogen name] is usually transmitted via the [transmission route] route to the human host.
 
OR
 
Following transmission/ingestion, the [pathogen] uses the [entry site] to invade the [cell name] cell.
 
OR
 
 
[Disease or malignancy name] arises from [cell name]s, which are [cell type] cells that are normally involved in [function of cells].
 
OR
 
The progression to [disease name] usually involves the [molecular pathway].
 
OR
 
The pathophysiology of [disease/malignancy] depends on the histological subtype.


==Pathophysiology==
==Pathophysiology==
Line 38: Line 13:
[[image:Diagram of the small bowel 01 CRUK 045.jpg|thumb|300px|Diagram of the small bowel 01. Source: Wikimedia.org By Cancer Research UK - Original email from CRUK, CC BY-SA 4.0,<ref name="urlFile:Diagram of the small bowel 01 CRUK 045.svg - Wikimedia Commons">{{cite web |url=https://commons.wikimedia.org/w/index.php?curid=34332940 |title=File:Diagram of the small bowel 01 CRUK 045.svg - Wikimedia Commons |format= |work= |accessdate=}}</ref>]]
[[image:Diagram of the small bowel 01 CRUK 045.jpg|thumb|300px|Diagram of the small bowel 01. Source: Wikimedia.org By Cancer Research UK - Original email from CRUK, CC BY-SA 4.0,<ref name="urlFile:Diagram of the small bowel 01 CRUK 045.svg - Wikimedia Commons">{{cite web |url=https://commons.wikimedia.org/w/index.php?curid=34332940 |title=File:Diagram of the small bowel 01 CRUK 045.svg - Wikimedia Commons |format= |work= |accessdate=}}</ref>]]
|}
|}
The [[small intestine]] has an average length of 5.5-6 meter and is responsible for [[digestion]] and [[absorption]] of food and [[nutrients]]. Three portions of [[small intestine]] are [[duodenum]], [[jejunum]], and [[ileum]]. There is an anatomic gradient for [[absorption]] throughout the [[gastrointestinal tract]].<ref name="pmid24500909">{{cite journal |vauthors=Tappenden KA |title=Pathophysiology of short bowel syndrome: considerations of resected and residual anatomy |journal=JPEN J Parenter Enteral Nutr |volume=38 |issue=1 Suppl |pages=14S–22S |year=2014 |pmid=24500909 |doi=10.1177/0148607113520005 |url=}}</ref><ref name="ThomsonDrozdowski2003">{{cite journal|last1=Thomson|first1=Alan B.R.|last2=Drozdowski|first2=Laurie|last3=Iordache|first3=Claudiu|last4=Thomson|first4=Ben K.A.|last5=Vermeire|first5=Severine|last6=Clandinin|first6=M. Tom|last7=Wild|first7=Gary|journal=Digestive Diseases and Sciences|volume=48|issue=8|year=2003|pages=1546–1564|issn=01632116|doi=10.1023/A:1024719925058}}</ref>
The [[small intestine]] has an average length of 5.5-6 meters and is responsible for [[digestion]] and [[absorption]] of food and [[nutrients]]. Three portions of [[small intestine]] are [[duodenum]], [[jejunum]], and [[ileum]]. There is an [[anatomic]] gradient for [[absorption]] throughout the [[gastrointestinal tract]].<ref name="pmid24500909">{{cite journal |vauthors=Tappenden KA |title=Pathophysiology of short bowel syndrome: considerations of resected and residual anatomy |journal=JPEN J Parenter Enteral Nutr |volume=38 |issue=1 Suppl |pages=14S–22S |year=2014 |pmid=24500909 |doi=10.1177/0148607113520005 |url=}}</ref><ref name="ThomsonDrozdowski2003">{{cite journal|last1=Thomson|first1=Alan B.R.|last2=Drozdowski|first2=Laurie|last3=Iordache|first3=Claudiu|last4=Thomson|first4=Ben K.A.|last5=Vermeire|first5=Severine|last6=Clandinin|first6=M. Tom|last7=Wild|first7=Gary|journal=Digestive Diseases and Sciences|volume=48|issue=8|year=2003|pages=1546–1564|issn=01632116|doi=10.1023/A:1024719925058}}</ref>
*The [[duodenum]], first portion of [[small intestine]], is responsible for the breakdown of food in the [[small intestine]]. [[Brunner's glands]], which secrete [[mucus]], are found in the [[duodenum]].
*[[Duodenum]] is the first part of the [[intestine]] located after the [[stomach]] and receives partially digested acidic [[chyme]] from the [[stomach]]. [[Brunner's glands]], which secrete [[alkaline]] rich [[mucin]] are also found in the [[duodenum]]. This [[alkaline]] rich [[mucin]] plays a protective role against the [[acidic]] contents received from the [[stomach]].
*The [[jejunum]], second portion of [[small intestine]], is responsible to absorb [[Nutrient|nutrients]]. The inner surface of the [[jejunum]] is covered in [[villus|villi]], which increase the surface area of [[Tissue (biology)|tissue]] available to absorb [[Nutrient|nutrients]] from the [[Gastrointestinal tract|gut]] contents. The [[Villus|villi]] in the [[jejunum]] are much longer than in the [[duodenum]] or [[ileum]]. It has many large [[circular folds]] in its [[submucosa]] called [[Circular folds|plicae circulares]], which increase the surface area for [[nutrient]] [[absorption]].
*The [[jejunum]] (second portion of [[small intestine]]) is responsible for absorption of [[Nutrient|nutrients]]. The inner surface of the [[jejunum]] is covered with [[villus|villi]], which increase the surface area of [[Tissue (biology)|tissue]] available to absorb [[Nutrient|nutrients]] from the [[Gastrointestinal tract|gut]] contents. The [[Villus|villi]] in the [[jejunum]] are much longer than in the [[duodenum]] or [[ileum]]. It has many large [[circular folds]] in its [[submucosa]] called [[Circular folds|plicae circulares]], which increase the [[surface area]] for [[nutrient]] [[absorption]].
*The [[ileum]], third portion of [[small intestine]], is responsible to absorb [[vitamin B12]] and [[bile salts]] and whatever products of [[digestion]] that were not absorbed by the [[jejunum]]. Its surface is made up of folds, mainly [[villi]] and [[microvilli]]. Therefore the [[ileum]] has an extremely large surface area both for the [[adsorption]] of [[enzymes]] and for the [[absorption]] of products of [[digestion]]. The diffuse neuroendocrine system (DNES) [[Cell (biology)|cells]] that line the [[ileum]] contain the [[protease]] and [[carbohydrase]] [[enzymes]] ([[gastrin]], [[secretin]], [[cholecystokinin]]) responsible for the final stages of [[protein]] and [[carbohydrate]] [[digestion]].
*The [[ileum]] (third portion of [[small intestine]]) is responsible for absorption of [[vitamin B12]] and [[bile salts]] and whatever products of [[digestion]] that were not absorbed by the [[jejunum]]. Its surface is made up of folds, mainly [[villi]] and [[microvilli]]. Therefore the [[ileum]] has an extremely large surface area both for the [[adsorption]] of [[enzymes]] and for the [[absorption]] of products of [[digestion]]. The diffuse [[neuroendocrine system]] (DNES) [[Cell (biology)|cells]] that line the [[ileum]] contain [[protein]] and [[carbohydrate]] digesting enzymes ([[gastrin]], [[secretin]], [[cholecystokinin]]), which are responsible for the final stages of [[protein]] and [[carbohydrate]] [[digestion]].
 
===Pathogenesis===
===Pathogenesis===
*Short bowel syndrome is the result of [[bowel resection]] following various causes including [[Crohn's disease]], [[Cancer|malignancies]], [[ischemia]], and [[Physical trauma|trauma]].
*Short bowel syndrome is the result of [[bowel resection]] following [[Crohn's disease]], [[Cancer|malignancies]], [[ischemia]], and [[Physical trauma|trauma]].<ref name="pmid11873098">{{cite journal |vauthors=Sundaram A, Koutkia P, Apovian CM |title=Nutritional management of short bowel syndrome in adults |journal=J. Clin. Gastroenterol. |volume=34 |issue=3 |pages=207–20 |year=2002 |pmid=11873098 |doi= |url=}}</ref>
*The [[small intestine]] has a very good [[adaptation]] following [[bowel resection]] of up to half of the [[Small intestine|small bowel]] length. However, the [[small intestine]] less than 2 meters is considered as short bowel syndrome and requires [[Nutrition|nutritional]] therapy to prevent [[malnutrition]].<ref name="EçaBarbosa2016">{{cite journal|last1=Eça|first1=Rosário|last2=Barbosa|first2=Elisabete|title=Short bowel syndrome: treatment options|journal=Journal of Coloproctology|volume=36|issue=4|year=2016|pages=262–272|issn=22379363|doi=10.1016/j.jcol.2016.07.002}}</ref>
*The [[small intestine]] has a very good [[adaptation]] following [[bowel resection]] of up to half of the [[Small intestine|small bowel]] length. However, a [[small intestine]] length less than 2 meters is considered as short bowel syndrome and requires [[Nutrition|nutritional]] therapy to prevent [[malnutrition]].<ref name="EçaBarbosa2016">{{cite journal|last1=Eça|first1=Rosário|last2=Barbosa|first2=Elisabete|title=Short bowel syndrome: treatment options|journal=Journal of Coloproctology|volume=36|issue=4|year=2016|pages=262–272|issn=22379363|doi=10.1016/j.jcol.2016.07.002}}</ref>


==== Post bowel resection adaptation ====
==== Post bowel resection adaptation ====
*[[Adaptation]] is the specific ability of the [[intestine]] to increase its capacity to [[Absorption|absorb]] [[Nutrient|nutrients]] following loss of its surface and length.  
*[[Adaptation]] is the specific ability of the [[intestine]] to increase its capacity to [[Absorption|absorb]] [[Nutrient|nutrients]] following loss of its surface area and length.<ref name="Warner2013">{{cite journal|last1=Warner|first1=Brad W.|title=Adaptation: Paradigm for the gut and an academic career|journal=Journal of Pediatric Surgery|volume=48|issue=1|year=2013|pages=20–26|issn=00223468|doi=10.1016/j.jpedsurg.2012.10.014}}</ref><ref name="RowlandMcMellen2012">{{cite journal|last1=Rowland|first1=Kathryn J.|last2=McMellen|first2=Mark E.|last3=Wakeman|first3=Derek|last4=Wandu|first4=Wambul S.|last5=Erwin|first5=Christopher R.|last6=Warner|first6=Brad W.|title=Enterocyte expression of epidermal growth factor receptor is not required for intestinal adaptation in response to massive small bowel resection|journal=Journal of Pediatric Surgery|volume=47|issue=9|year=2012|pages=1748–1753|issn=00223468|doi=10.1016/j.jpedsurg.2012.03.089}}</ref>
*There will be structural, motility and functional changes in the remaining [[intestine]] to compensate its loss.  
*There will be structural, motility and functional changes in the remaining [[intestine]] to compensate its loss.<ref name="pmid24500909">{{cite journal |vauthors=Tappenden KA |title=Pathophysiology of short bowel syndrome: considerations of resected and residual anatomy |journal=JPEN J Parenter Enteral Nutr |volume=38 |issue=1 Suppl |pages=14S–22S |year=2014 |pmid=24500909 |doi=10.1177/0148607113520005 |url=}}</ref><ref name="EçaBarbosa2016">{{cite journal|last1=Eça|first1=Rosário|last2=Barbosa|first2=Elisabete|title=Short bowel syndrome: treatment options|journal=Journal of Coloproctology|volume=36|issue=4|year=2016|pages=262–272|issn=22379363|doi=10.1016/j.jcol.2016.07.002}}</ref>
*Changes usually starts in the first 24 hours following [[bowel resection]].  
*Changes usually starts in the first 24 hours following [[bowel resection]].<ref name="pmid16207689">{{cite journal |vauthors=Matarese LE, O'Keefe SJ, Kandil HM, Bond G, Costa G, Abu-Elmagd K |title=Short bowel syndrome: clinical guidelines for nutrition management |journal=Nutr Clin Pract |volume=20 |issue=5 |pages=493–502 |year=2005 |pmid=16207689 |doi=10.1177/0115426505020005493 |url=}}</ref>
{| class="wikitable"
{| class="wikitable"
!Change
! align="center" style="background:#4479BA; color: #FFFFFF;" + |Change
!Main features
! align="center" style="background:#4479BA; color: #FFFFFF;" + |Main features
!
!
|-
|-
|Structural changes
|'''Structural changes'''
|
|
|
|
* Increase in the [[Absorptive state|absorptive]] surface area
* [[Small intestine|Small bowel]] dilation
* [[Crypt (anatomy)|Crypt]] cells [[hyperplasia]]
* [[Villous folds|Villous]] [[Hypertrophy (medical)|hypertrophy]]
* Local [[angiogenesis]]
* Increased production of [[Gastrointestinal tract|enteral]] [[hormones]] and pancreaticobiliary secretions
|-
|-
|Motility changes
|'''Motility changes'''
|
|
|
|
* Greater [[motility]] during the initial phase
* Reduced [[motility]] during the adaptive phase
|-
|-
|Functional changes
|'''Functional changes'''
|
|
|
|
* Increased activity of [[enzymes]]
* Increased level of [[Tropic hormone|trophic factors]]
* Increased level of carrier [[Protein|proteins]]
|}
|}
*[[Adaptation]] depends on multiple factors including individual, [[Intestine|intestinal]] and [[Therapy|therapeutic]] measurements.  
*[[Adaptation]] depends on multiple factors including individual, [[Intestine|intestinal]] and [[Therapy|therapeutic]] measurements.<ref name="Warner2013">{{cite journal|last1=Warner|first1=Brad W.|title=Adaptation: Paradigm for the gut and an academic career|journal=Journal of Pediatric Surgery|volume=48|issue=1|year=2013|pages=20–26|issn=00223468|doi=10.1016/j.jpedsurg.2012.10.014}}</ref>
*[[Adaptation]] is usually occurred during the first two years after the [[bowel resection]].
*[[Adaptation]] usually occurrs during the first two years after the [[bowel resection]].
*Successful [[adaptation]] depends on the length of remaining [[intestine]], portion of the resected [[intestine]], early introduction of [[nutrition]] therapy.  
*Successful [[adaptation]] depends on the length of remaining [[intestine]], portion of the resected [[intestine]], early introduction of [[nutrition]] therapy. Total [[Intestine|intestinal]] [[adaptation]] defines as when patient is weaned from [[Total parenteral nutrition|parenteral nutrition]].<ref name="Wall2013">{{cite journal|last1=Wall|first1=Elizabeth A.|title=An Overview of Short Bowel Syndrome Management: Adherence, Adaptation, and Practical Recommendations|journal=Journal of the Academy of Nutrition and Dietetics|volume=113|issue=9|year=2013|pages=1200–1208|issn=22122672|doi=10.1016/j.jand.2013.05.001}}</ref>
*Following the [[bowel resection]], [[adaptation]] occurs in three phases including acute, adaptive, and maintenance phases.
*Following the [[bowel resection]], [[adaptation]] occurs in three phases including acute, adaptive, and maintenance phases.<ref name="pmid17198059">{{cite journal |vauthors=Misiakos EP, Macheras A, Kapetanakis T, Liakakos T |title=Short bowel syndrome: current medical and surgical trends |journal=J. Clin. Gastroenterol. |volume=41 |issue=1 |pages=5–18 |year=2007 |pmid=17198059 |doi=10.1097/01.mcg.0000212617.74337.e9 |url=}}</ref>
{| class="wikitable"
{| class="wikitable"
!
! colspan="3" align="center" style="background:#4479BA; color: #FFFFFF;" + |Intestinal adaptation
!Intestinal adaptation
!
!
|-
|-
!Phase
! align="center" style="background:#4479BA; color: #FFFFFF;" + |Phase
!Duration
! align="center" style="background:#4479BA; color: #FFFFFF;" + |Duration
!Main feature
! align="center" style="background:#4479BA; color: #FFFFFF;" + |Main feature
!
|-
|-
|Acute phase
! align="center" style="background:#4479BA; color: #FFFFFF;" + |'''Acute phase'''
|
|1 to 3 months
|
|
|
* [[Hypovolemia|Fluid loss]]
* Poor [[absorption]] of all [[Nutrient|nutrients]], including [[Carbohydrate|carbohydrates]], [[Protein|proteins]], [[fat]], [[Electrolyte|electrolytes]], [[Mineral|minerals]] and trace elements
* Dysmotility
* Hypergastrinemia
|-
|-
|Adaptive phase
! align="center" style="background:#4479BA; color: #FFFFFF;" + |'''Adaptive phase'''
|
|1 to 2 years
|
|
|
* Reaching 90% to 95% of the bowel [[adaptation]] potential
* [[Enterocyte]] and [[Villous folds|villous]] [[hyperplasia]]
* Increased [[Mucous membrane|mucosal]] surface area
* Converting unabsorbed [[Carbohydrate|carbohydrates]] into absorbable [[short-chain fatty acids]]
* Gaining weight
* Stabilization of [[fluid]] and [[electrolyte]] levels
|-
|-
|Maintenance phase
! align="center" style="background:#4479BA; color: #FFFFFF;" + |'''Maintenance phase'''
|
|Following adaptive phase
|
|
|
* Reaching the maximum bowel [[adaptation]] potential
|}
|}
* There are factors which stimulate the intestinal adaptation, including:
* There are factors which stimulate the [[Intestine|intestinal]] [[adaptation]], including:<ref name="pmid14642862">{{cite journal |vauthors=Vanderhoof JA, Young RJ |title=Enteral and parenteral nutrition in the care of patients with short-bowel syndrome |journal=Best Pract Res Clin Gastroenterol |volume=17 |issue=6 |pages=997–1015 |year=2003 |pmid=14642862 |doi= |url=}}</ref>
** Oral nutrients
** Oral [[Nutrient|nutrients]]
** Soluble fibres such as polysaccharides present in pectin and soy
** Soluble [[Fiber|fibres]] such as [[Polysaccharide|polysaccharides]] present in [[pectin]] and [[soy]]
** hydrolysed or whole-protein formula
** Hydrolysed or whole protein formula
** Polyamines
** [[Polyamine|Polyamines]]
** Long-chain triglycerides and SCFA 
** Long-chain [[Triglyceride|triglycerides]] and [[short-chain fatty acids]]
** Proglucagon mediator, glucagon-like peptide 2 (GLP-2)
** [[Glucagon-like peptide 2 receptor|Glucagon-like peptide 2]] (GLP-2)
** Secretin
** [[Secretin]]
** Cholecystokinin
** [[Cholecystokinin]]
** Neurotensin
** [[Neurotensin]]
** Insulin-like growth factor I, also known as somatomedin-C
** [[Insulin-like growth factor 1|Insulin-like growth factor I]]
** Glutamine
** [[Glutamine]]
* There are factors which decrease the intestinal adaptation, including:  
* There are factors which decrease the [[Intestine|intestinal]] [[adaptation]], including:  
** Starvation
** [[Starvation]]
** Absence of luminal nutrients 
** Absence of luminal [[Nutrient|nutrients]] 
** Absence of pancreato-biliary secretions 
** Absence of pancreato-biliary secretions 
** Monosaccharides
** [[Monosaccharide|Monosaccharides]]


==== Malabsorption ====
==== Malabsorption ====
Line 141: Line 122:


==Associated Conditions==
==Associated Conditions==
Short bowel syndrome is associated with following pathologies:
Short bowel syndrome might be associated with following pathologies:
*[[Mesenteric ischemia|Mesenteric vascular events]] including [[thrombosis]] or [[occlusion]] of the [[superior mesenteric artery]] or [[vein]]
*[[Mesenteric ischemia|Mesenteric vascular events]] including [[thrombosis]] or [[occlusion]] of the [[superior mesenteric artery]] or [[vein]]
*[[Crohn's disease]]
*[[Crohn's disease]]
Line 147: Line 128:
*[[Radiation enteropathy|Radiation enteritis]]
*[[Radiation enteropathy|Radiation enteritis]]
*[[Volvulus]]
*[[Volvulus]]
*Adhesions
*[[Adhesion (medicine)|Adhesions]]
*Jejunoileal bypass surgery to treat [[obesity]]
*Jejunoileal bypass surgery to treat [[obesity]]
*[[Physical trauma|Trauma]] to the small intestine
*[[Physical trauma|Trauma]] to the [[small intestine]]
*Internal hernia
*[[Internal hernia]]
 
==Gross Pathology==
==Gross Pathology==
*On gross pathology, the resected [[Intestine|bowel]] may show the underlying causes including [[Crohn's disease]], [[Cancer|malignancies]] or [[ischemia]].  
*On gross pathology, the resected [[Intestine|bowel]] may show the underlying causes including [[Crohn's disease]], [[Cancer|malignancies]] or [[ischemia]].  
Line 167: Line 149:
==References==
==References==
{{Reflist|2}}
{{Reflist|2}}
[[Category:Medicine]]
[[Category:Gastroenterology]]
[[Category:Surgery]]
[[Category:Up-To-Date]]

Latest revision as of 00:10, 30 July 2020

Short bowel syndrome Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Short bowel syndrome from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Study of Choice

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

X-ray

Echocardiography and Ultrasound

CT scan

MRI

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Short bowel syndrome pathophysiology On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Short bowel syndrome pathophysiology

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Short bowel syndrome pathophysiology

CDC on Short bowel syndrome pathophysiology

Short bowel syndrome pathophysiology in the news

Blogs on Short bowel syndrome pathophysiology

Directions to Hospitals Treating Short bowel syndrome

Risk calculators and risk factors for Short bowel syndrome pathophysiology

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sadaf Sharfaei M.D.[2]

Overview

Short bowel syndrome occurrs as a result of bowel resection following various diseases of the gut such as Crohn's disease, malignancies, ischemia, and trauma. Short bowel syndrome occurs when the length of the small intestine is less than 2 meters and requires nutritional therapy to prevent malnutrition. Post bowel resection, adaptation might occur which includes structural, motility and functional changes in the remaining intestine. Changes usually start in the first 24 hours following bowel resection and last for about two years. Adaptation depends upon multiple factors including individual, intestinal and therapeutic measurements. Following bowel resectionadaptation occurs in three phases including acute, adaptive, and maintenance phases. Successful adaptation depends on the length of remaining intestine, portion of the resected intestine, and early introduction of nutrition therapy. The term total intestinal adaptation is used when the patient is weaned from parenteral nutrition. The main reason for malabsorption following bowel resection is reduced absorptive capacity of the small intestine due to loss of surface area. On gross and microscopic examination, the resected bowel segment may show the underlying causes including Crohn's diseasemalignancies or ischemia.

Pathophysiology

Physiology

Diagram of the small bowel 01. Source: Wikimedia.org By Cancer Research UK - Original email from CRUK, CC BY-SA 4.0,[1]

The small intestine has an average length of 5.5-6 meters and is responsible for digestion and absorption of food and nutrients. Three portions of small intestine are duodenum, jejunum, and ileum. There is an anatomic gradient for absorption throughout the gastrointestinal tract.[2][3]

Pathogenesis

Post bowel resection adaptation

Change Main features
Structural changes
Motility changes
  • Greater motility during the initial phase
  • Reduced motility during the adaptive phase
Functional changes
Intestinal adaptation
Phase Duration Main feature
Acute phase 1 to 3 months
Adaptive phase 1 to 2 years
Maintenance phase Following adaptive phase

Malabsorption

Associated Conditions

Short bowel syndrome might be associated with following pathologies:

Gross Pathology

Terminal ileum resected for Crohn's disease. By PPSE15 - Own work, CC BY-SA 4.0[12]
Partial Jejunum affected by morbus Crohn. Source: Wikimedia.org By Jaroslav Cehovsky - Camera, Public Domain[13]

Microscopic Pathology

References

  1. "File:Diagram of the small bowel 01 CRUK 045.svg - Wikimedia Commons".
  2. 2.0 2.1 Tappenden KA (2014). "Pathophysiology of short bowel syndrome: considerations of resected and residual anatomy". JPEN J Parenter Enteral Nutr. 38 (1 Suppl): 14S–22S. doi:10.1177/0148607113520005. PMID 24500909.
  3. Thomson, Alan B.R.; Drozdowski, Laurie; Iordache, Claudiu; Thomson, Ben K.A.; Vermeire, Severine; Clandinin, M. Tom; Wild, Gary (2003). Digestive Diseases and Sciences. 48 (8): 1546–1564. doi:10.1023/A:1024719925058. ISSN 0163-2116. Missing or empty |title= (help)
  4. Sundaram A, Koutkia P, Apovian CM (2002). "Nutritional management of short bowel syndrome in adults". J. Clin. Gastroenterol. 34 (3): 207–20. PMID 11873098.
  5. 5.0 5.1 Eça, Rosário; Barbosa, Elisabete (2016). "Short bowel syndrome: treatment options". Journal of Coloproctology. 36 (4): 262–272. doi:10.1016/j.jcol.2016.07.002. ISSN 2237-9363.
  6. 6.0 6.1 Warner, Brad W. (2013). "Adaptation: Paradigm for the gut and an academic career". Journal of Pediatric Surgery. 48 (1): 20–26. doi:10.1016/j.jpedsurg.2012.10.014. ISSN 0022-3468.
  7. Rowland, Kathryn J.; McMellen, Mark E.; Wakeman, Derek; Wandu, Wambul S.; Erwin, Christopher R.; Warner, Brad W. (2012). "Enterocyte expression of epidermal growth factor receptor is not required for intestinal adaptation in response to massive small bowel resection". Journal of Pediatric Surgery. 47 (9): 1748–1753. doi:10.1016/j.jpedsurg.2012.03.089. ISSN 0022-3468.
  8. Matarese LE, O'Keefe SJ, Kandil HM, Bond G, Costa G, Abu-Elmagd K (2005). "Short bowel syndrome: clinical guidelines for nutrition management". Nutr Clin Pract. 20 (5): 493–502. doi:10.1177/0115426505020005493. PMID 16207689.
  9. Wall, Elizabeth A. (2013). "An Overview of Short Bowel Syndrome Management: Adherence, Adaptation, and Practical Recommendations". Journal of the Academy of Nutrition and Dietetics. 113 (9): 1200–1208. doi:10.1016/j.jand.2013.05.001. ISSN 2212-2672.
  10. Misiakos EP, Macheras A, Kapetanakis T, Liakakos T (2007). "Short bowel syndrome: current medical and surgical trends". J. Clin. Gastroenterol. 41 (1): 5–18. doi:10.1097/01.mcg.0000212617.74337.e9. PMID 17198059.
  11. Vanderhoof JA, Young RJ (2003). "Enteral and parenteral nutrition in the care of patients with short-bowel syndrome". Best Pract Res Clin Gastroenterol. 17 (6): 997–1015. PMID 14642862.
  12. "File:ResectedIleum.jpg - Wikimedia Commons". External link in |title= (help)
  13. "File:Crohn Jejunum.PNG - Wikimedia Commons".