Editing Meckel's diverticulum (section)

==Signs and symptoms==
The majority of people with a Meckel's diverticulum are [[asymptomatic]]. An asymptomatic Meckel's diverticulum is called a ''silent'' Meckel's diverticulum.<ref name="pmid19103339">{{cite journal |vauthors=Thurley PD, Halliday KE, Somers JM, Al-Daraji WI, Ilyas M, Broderick NJ |title=Radiological features of Meckel's diverticulum and its complications |journal=Clin Radiol |volume=64 |issue=2 |pages=109–18 |date=February 2009 |pmid=19103339 |doi=10.1016/j.crad.2008.07.012 }}</ref> If symptoms do occur, they typically appear before the age of two years.<ref name="Meckel's Diverticulum">{{cite web |url= https://www.lecturio.com/concepts/meckels-diverticulum/| title= Meckel's Diverticulum
|website=The Lecturio Medical Concept Library |access-date= 10 August 2021}}</ref> The most common presenting symptom is painless [[rectal bleeding]] such as [[melaena]]-like black offensive stools, followed by [[intestinal obstruction]], [[volvulus]] and [[intussusception (medical disorder)|intussusception]]. Occasionally, Meckel's diverticulitis may present with all the features of [[acute appendicitis]].<ref name="lecturio.com">{{cite web | url= https://www.lecturio.com/concepts/appendicitis/ | title= Appendicitis (Differential Diagnosis)| website= The Lecturio Medical Concept Library | access-date= 1 July 2021}}</ref> Also, severe pain in the [[epigastric region]] is experienced by the person along with bloating in the epigastric and umbilical regions. At times, the symptoms are so painful that they may cause sleepless nights with acute pain felt in the foregut region, specifically in the [[epigastric]] and [[Navel|umbilical]] regions.{{citation needed|date=August 2020}} In some cases, bleeding occurs without warning and may stop spontaneously. The symptoms can be extremely painful, often mistaken as just stomach pain resulting from not eating or constipation.{{citation needed|date=August 2020}} Rarely, a Meckel's diverticulum containing ectopic pancreatic tissue can present with abdominal pain and increased serum amylase levels, mimicking acute pancreatitis.<ref>{{cite journal |vauthors=Darlington CD, Anitha GF |title=Meckel's Diverticulitis Masquerading as Acute Pancreatitis: A Diagnostic Dilemma |journal=Indian J Crit Care Med |volume=21 |issue=11 |pages=789–792 |date=November 2017 |pmid=29279643 |pmc=5699010 |doi=10.4103/ijccm.IJCCM_317_17 |doi-access=free}}</ref>

===Complications===
The lifetime risk for a person with Meckel's diverticulum to develop certain [[complication (medicine)|complication]]s is about 4–6%. Gastrointestinal bleeding, [[peritonitis]] or [[intestinal obstruction]] may occur in 15–30% of symptomatic people (Table 1). On rare occasions the diverticulum can herniate through the abdominal wall also known as a [[Littre Hernia|Littre hernia.]] Only 6.4% of all complications require surgical treatment, and untreated Meckel's diverticulum has a [[mortality rate]] of 2.5–15%.<ref name="Larsen"/>

Table 1 – Complications of Meckel's Diverticulum:<ref name="Johnston"/>
{| class="wikitable" style="text-align: center;"
|-
! style="border-style: solid; center; border-width: 1px; text-align: left;"| Complications
! style="border-style: solid; center; border-width: 1px"| Percentage of symptomatic Meckel's Diverticulum (%)
|-
| style="border-style: solid; border-width: 1px; text-align: left;"| [[Haemorrhage]]
| style="border-style: solid; border-width: 1px"| 20–30
|-
| style="border-style: solid; border-width: 1px; text-align: left;"| [[Intestinal obstruction]]
| style="border-style: solid; border-width: 1px"| 20–25
|-
| style="border-style: solid; border-width: 1px; text-align: left;"| [[Diverticulitis]]
| style="border-style: solid; border-width: 1px"| 10–20
|-
| style="border-style: solid; border-width: 1px; text-align: left;"| Umbilical anomalies
| style="border-style: solid; border-width: 1px"| ≤10
|-
| style="border-style: solid; border-width: 1px; text-align: left;"| [[Neoplasm]]
| style="border-style: solid; border-width: 1px"| 0.5-2
|}

====Bleeding====
Bleeding of the diverticulum is most common in young children, especially in males who are less than 2 years of age.<ref name="Sagar">{{cite journal |author1=Sagar J. |author2=Kumar V. |author3=Shah D. K. | year = 2006 | title = Meckel's diverticulum: A systematic review | journal = Journal of the Royal Society of Medicine | volume = 99 | issue = 10| pages = 501–505 | doi = 10.1177/014107680609901011 | pmid = 17021300 | pmc = 1592061 }}</ref> Symptoms may include bright red blood in stools ([[hematochezia]]), weakness, abdominal tenderness or pain, and even [[anaemia]] in some cases.<ref name="Karaman">{{cite journal |author1=Karaman A. |author2=Karaman I. |author3=Cavusoaglu Y. H. |author4=Erdoagan D. |author5=Aslan M. K. | year = 2010 | title = Management of asymptomatic or incidental meckels diverticulum | journal = Indian Pediatrics | volume = 47 | issue = 12| pages = 1055–1057 | doi = 10.1007/s13312-010-0176-1 | pmid = 19671945 |s2cid=33255331 }}</ref>

'''Bleeding may be caused by:'''
* Ectopic gastric or pancreatic mucosa:
# Where diverticulum contains embryonic remnants of mucosa of other tissue types.
# Secretion of [[gastric acid]] or alkaline [[pancreatic juice]] from the ectopic mucosa leads to ulceration in the adjacent ileal mucosa i.e. peptic or pancreatic ulcer.<ref name="Hig">{{cite journal |author1=Higaki S. |author2=Saito Y. |author3=Akazawa A. |author4=Okamoto T. |author5=Hirano A. |author6=Takeo Y. |author7=Okita K. | year = 2001 | title = Bleeding ''Meckel's diverticulum'' in an adult | journal = Hepato-Gastroenterology | volume = 48 | issue = 42| pages = 1628–1630 | pmid = 11813588 }}</ref>
# Pain, bleeding or perforation of the bowel at the diverticulum may result.
# Mechanical stimulation may also cause erosion and ulceration.
* Gastrointestinal bleeding may be self-limiting but chronic bleeding may lead to [[iron deficiency anaemia]].<ref name="A-O ">{{cite journal |author1=Al-Onaizi I. |author2=Al-Awadi F. |author3=Al-Dawood A. L. | year = 2002 | title = Iron deficiency anaemia: An unusual complication of ''Meckel's diverticulum'' | journal = Medical Principles and Practice | volume = 11 | issue = 4| pages = 214–217 | doi = 10.1159/000065810 |pmid=12424418 | doi-access = free }}</ref>

'''The appearance of stools may indicate the nature of the bleeding:'''
* ''Tarry stools'': Alteration of blood produced by slow bowel transit due to minor bleeding in upper gastrointestinal tract
* ''Bright red blood stools'': Brisk bleeding
* ''Stools with blood streak'': [[Anal fissure]]
* ''"Currant jelly" stools'': [[Ischaemia]] of the intestine leads to copious mucus production and may indicate that one part of the bowel [[invagination|invaginates]] into another ([[intussusception (medical disorder)|intussusception]]).

====Diverticulitis====

Inflammation of the diverticulum can mimic symptoms of appendicitis, i.e., periumbilical tenderness and intermittent crampy abdominal pain. Perforation of the inflamed diverticulum can result in peritonitis. Diverticulitis can also cause [[adhesion]]s, leading to intestinal obstruction.<ref name="Sharma">{{cite journal |author1=Sharma R. |author2=Jain V. | year = 2008 | title = Emergency surgery for Meckel's diverticulum | journal = World J Emerg Surg | volume = 3 | issue = 27| pages = 1–8 | doi = 10.1186/1749-7922-3-27 |pmid=18700974 |pmc=2533303 |doi-access=free }}</ref>

'''Diverticulitis may result from:'''
* Association with the mesodiverticular band attaching to the diverticulum tip where torsion has occurred, causing inflammation and ischaemia.<ref name="Tan">{{cite journal |vauthors=Tan YM, Zheng ZX |title=Recurrent torsion of a giant Meckel's diverticulum |journal=Dig Dis Sci |volume=50 |issue=7 |pages=1285–7 |date=July 2005 |pmid=16047474 |doi=10.1007/s10620-005-2774-7 }}</ref>
* Peptic ulceration resulting from ectopic gastric mucosa of the diverticulum
* Perforation by trauma or ingested foreign material (e.g., vegetable stalks, seeds, or fish/chicken bones) that become lodged in the Meckel's diverticulum.<ref name="Drake"/>
* Luminal obstruction due to [[tumor]]s, [[enterolith]], or another foreign body, causing stasis or bacterial infection.<ref name="Mattei "/>
* Association with acute appendicitis<ref name="lecturio.com"/>

====Intestinal obstruction====

'''Symptoms:''' Vomiting, abdominal pain and severe or complete [[constipation]].<ref name="Pariza">{{cite journal |vauthors=Pariza G, Mavrodin CI, Ciurea M |title=[Complicated Meckel's diverticulum in adult pathology] |language=Romanian |journal=Chirurgia (Bucur) |volume=104 |issue=6 |pages=745–8 |date=2009 |pmid=20187476 }}</ref>
* The vitelline vessels remnant that connects the diverticulum to the umbilicus may form a fibrous or twisting band ([[volvulus]]), trapping the small intestine and causing obstruction. Localised periumbilical pain may be experienced in the right lower quadrant (like appendicitis).<ref name="Mattei "/>
* "Incarceration": when a Meckel's diverticulum is constricted in an [[inguinal hernia]], forming a [[Littre hernia|Littré hernia]] that obstructs the intestine.<ref name="Martin">{{cite book |first=E. |last=Martin |title=Concise colour medical dictionary |publisher=Oxford University Press |edition=5th |date=2010 |isbn=978-0-19-955715-8 |oclc=1193397604 }}</ref>
* Chronic diverticulitis causing [[Stricture (medicine)|stricture]]
* Strangulation of the diverticulum in the [[obturator foramen]].
* Tumors e.g. [[carcinoma]]: direct spread of an [[adenocarcinoma]] arising in the diverticulum may lead to obstruction
* [[Lithiasis]], stones that are formed in Meckel's diverticulum can:
# Extrude into the terminal ileum, leading to obstruction
# Induce local inflammation and intussusception.<ref name="Mattei "/>
* The diverticulum itself or a tumour within it may cause intussusception – for example, from the ileum to the colon – causing obstruction. Symptoms of this include "currant jelly" stools and a palpable lump in the lower abdomen.<ref name="Johnston">{{cite journal |author1=Johnston A. O. |author2=Moore T. | year = 1976 | title = Complications of ''Meckel's diverticulum'' | journal =  British Journal of Surgery| volume = 63 | issue = 6| pages = 453–454 | doi = 10.1002/bjs.1800630612 |pmid=1084202 |s2cid=29734423 }}</ref> This occurs when the diverticulum inverts into the lumen of the ileum, due to either:
# An ''active'' [[Peristalsis|peristaltic]] mechanism of the diverticulum that attempts to remove irritating factors
# A ''passive'' process such as the transit of food<ref name="Karaman"/>

====Umbilical anomalies====

Anomalies between the diverticulum and umbilicus may include the presence of a fibrous cord, [[cyst]], fistula, or sinus, leading to:<ref name="Sharma"/>
* Infection or [[excoriation]] of periumbilical skin, resulting in a discharging sinus
* Recurrent infection and healing of sinus
* Abscess formation in the abdominal wall
* Increased risk of volvulus formation and internal herniation

====Tumors====

[[Neoplasm]]s (tumors) in Meckel's diverticulum may cause bleeding, acute abdominal pain, gastrointestinal obstruction, perforation or intussusception. They may be [[benign tumor|benign]] or [[Cancer|malignant]].<ref name="Sharma" />
* '''Benign tumors''':
# [[Leiomyoma]]
# [[Lipoma]]
# Vascular and [[neuromuscular]] [[hamartoma]]
* '''Malignant tumors''':
# [[Carcinoid]]s: most common, 44%
# [[Mesenchymal]] tumors: [[Leiomyosarcoma]], peripheral nerve sheath and gastrointestinal [[stromal tumor]]s, 35%
# [[Adenocarcinoma]], 16%
# [[Desmoplastic]] small round cell tumor

====Other complications====
* A diverticulum inside a Meckel's diverticulum (daughter diverticula)
* Stones and [[phytobezoar]] (a [[bezoar]] of vegetable fibers) in Meckel's diverticulum
* Vesicodiverticular fistula<ref name="Johnston"/>