Editing Defecation (section)

==Disease==
Regular bowel movements determine the functionality and the health of the alimentary tracts in human body. Defecation is the most common regular bowel movement which eliminates waste from the human body. The frequency of defecation is hard to identify, which can vary from daily to weekly depending on individual bowel habits, the impact from the environment, and genetics.<ref>{{cite book |doi=10.1016/B978-0-12-803968-7.00026-5 |chapter=Defecation and Stools in Vegetarians |title=Vegetarian and Plant-Based Diets in Health and Disease Prevention |year=2017 |last1=Nath |first1=Preetam |last2=Singh |first2=Shivaram Prasad |pages=473–481 |isbn=978-0-12-803968-7 }}</ref> If defecation is delayed for a prolonged period the fecal matter may harden, resulting in [[constipation]]. If defecation occurs too fast, before excess liquid is absorbed, [[diarrhea]] may occur.<ref>{{cite news|author=NIH|url=https://www.nlm.nih.gov/medlineplus/bowelmovement.html|title=Bowel Movement|journal=MedlinePlus|access-date=13 September 2014}}</ref> Other associated symptoms can include abdominal bloating, abdominal pain, and abdominal distention.<ref>{{cite journal |last1=Lacy |first1=Brian E. |last2=Mearin |first2=Fermín |last3=Chang |first3=Lin |last4=Chey |first4=William D. |last5=Lembo |first5=Anthony J. |last6=Simren |first6=Magnus |last7=Spiller |first7=Robin |title=Bowel Disorders |journal=Gastroenterology |date=May 2016 |volume=150 |issue=6 |pages=1393–1407.e5 |doi=10.1053/j.gastro.2016.02.031 |pmid=27144627 |url=http://pdfs.semanticscholar.org/b584/2e286d265c0cd50e3d56ad9a0ce61686d376.pdf }}</ref> Disorders of the bowel can seriously impact quality of life and daily activities. The causes of functional bowel disorder are multifactorial, and dietary habits such as food intolerance and low fiber diet are considered to be the primary factors.<ref>{{cite journal |last1=Grace |first1=Sandra |last2=Barnes |first2=Larisa |last3=Reilly |first3=Wayne |last4=Vlass |first4=Ann |last5=de Permentier |first5=Patrick |title=An integrative review of dietetic and naturopathic approaches to functional bowel disorders |journal=Complementary Therapies in Medicine |date=December 2018 |volume=41 |pages=67–80 |doi=10.1016/j.ctim.2018.09.004 |pmid=30477867 |s2cid=53768740 }}</ref>

=== Constipation ===
{{main|Constipation}}
Constipation, also known as defecatory dysfunction, is difficulty experienced when passing stools. It is one of the most notable alimentary disorders that affects different age groups in the population. Common constipation is associated with abdominal distention, pain or bloating.<ref name=":13">{{Cite journal|last1=Hay|first1=Tyler|last2=Bellomo|first2=Ranaldo|last3=Rechnitzer|first3=Tom|last4=See|first4=Emily|last5=Abdelhamid|first5=Yasmine Ali|last6=Deane|first6=Adam|date=January 2019|title=Constipation, diarrhea, and prophylactic laxative bowel regimens in the critically ill: A systematic review and meta-analysis|journal=Journal of Critical Care|volume=52|pages=242–250|doi=10.1016/j.jcrc.2019.01.004|pmid=30665795|s2cid=58667995}}</ref> Research has revealed that chronic constipation complied with higher risk of cardiovascular events such as coronary heart disease and ischemic stroke, while associating with an increasing risk of mortality.<ref>{{Cite journal|last1=Sumida|first1=Keiichi|last2=Molnar|first2=Miklos Z|last3=Potukuchi|first3=Praveen K|last4=Thomas|first4=Fridtjof|last5=Ling|first5=Jun Lu|last6=Yamagata|first6=Kunihiro|last7=Zadeh|first7=Kamyar Kalantar|last8=Kovesdy|first8=Casba P|date=February 2019|title=Constipation and risk of death and cardiovascular events|journal=Atherosclerosis|volume=281|pages=114–120|doi=10.1016/j.atherosclerosis.2018.12.021|pmid=30658186|pmc=6399019}}</ref> Besides dietary factors, psychological traumas and 'pelvic floor disorders' can also cause chronic constipation and defecatory disorder respectively.<ref name=":13" /> Multiple interventions, including physical activities, 'high-fibre diet', probiotics<ref>{{cite journal |last1=Hod |first1=Keren |last2=Ringel |first2=Yehuda |title=Probiotics in functional bowel disorders |journal=Best Practice & Research Clinical Gastroenterology |date=February 2016 |volume=30 |issue=1 |pages=89–97 |doi=10.1016/j.bpg.2016.01.003 |pmid=27048900 }}</ref> and drug therapies can be widely and efficiently used to treat constipation and defecatory disorder.

=== Inflammatory bowel diseases ===
{{main|Inflammatory bowel disease}}
Inflammatory disease is characterized as long-lasting, chronic inflammation throughout the gastrointestinal tract. [[Crohn's disease]] (CD) and [[ulcerative colitis]] (UC) are two universal types of inflammatory bowel disease that have been studied over a century. They are closely related to different environmental risk factors, family genetics, and lifestyle choices such as smoking.<ref>{{Cite journal|last=Fiocchi|first=Claudio|date=1998|title=Inflammatory bowel disease: Etiology and pathogenesis|journal=Gastroenterology|volume=115|issue=1|pages=182–205|doi=10.1016/S0016-5085(98)70381-6|pmid=9649475}}</ref> Crohn's disease has been found to be related to immune disorders particularly.<ref name=":3">{{Cite journal|last1=Baumgart|first1=Daniel C|last2=Sandborn|first2=William J|date=November 2012|title=Crohn's disease|journal=The Lancet|volume=380|issue=9853|pages=1590–1605|doi=10.1016/S0140-6736(12)60026-9|pmid=22914295|s2cid=18672997|doi-access=free}}</ref> Different levels of cumulative intestinal injuries can cause different complications, such as fistulae, damage of bowel function, symptom recurrence, disability, etc.<ref>{{Cite journal|last1=Agrawal|first1=Manasi|last2=Colombel|first2=Jean-Frederic|date=2019|title=Treat-to-Target in Inflammatory Bowel Diseases, What Is the Target and How Do We Treat?|journal=Gastrointestinal Endoscopy Clinics of North America|volume=29|issue=3|pages=421–436|doi=10.1016/j.giec.2019.02.004|pmid=31078245|s2cid=132251418}}</ref> Patients can be children or adults. Recent research shows that immunodeficiency and monogenic disorders are the causes in young patients with inflammatory bowel diseases.<ref>{{Cite journal|last1=Kelsen|first1=Juridth R|last2=Russo|first2=Pierre|last3=Sullivan|first3=Kathleen E|date=February 2019|title=Early-Onset Inflammatory Bowel Disease|journal=Immunology and Allergy Clinics of North America|volume=39|issue=1|pages=63–79|doi=10.1016/j.iac.2018.08.008|pmid=30466773|pmc=6954002}}</ref> 

Common symptoms of inflammatory bowel diseases differ by the infection level, but may include severe abdominal pain, diarrhea, fatigue, and unexpected weight loss. [[Crohn's disease]] can lead to infection of any part of the digestive tract, including ileum to anus.<ref>{{Cite journal|title=Crohn's disease|journal=Medicine|volume=47|issue=6|last1=Mak|first1=Wing Yan|last2=Hart|first2=Alisa L|last3=Ng|first3=Siew C|year=2019|pages=377–387|doi=10.1016/j.mpmed.2019.03.007|s2cid=242228134}}</ref> Internal manifestations include diarrhea, abdomen pain, fever, chronic anaemia, etc. External manifestations include impact on skin, joints, eyes, and liver. Significantly reduced microbiota diversity inside the gastrointestinal tract can also be observed. Ulcerative colitis mainly affects the function of the large bowel, and its incidence rate is three times greater than that of Crohn's disease.<ref name=":5">{{Cite journal|last=Steed|first=Helen|date=May 2019|title=Ulcerative colitis|journal=Medicine|volume=47|issue=6|pages=371–376|doi=10.1016/j.mpmed.2019.03.001|s2cid=243328622}}</ref> In terms of clinical features, over 90 percent of patients exhibit constant diarrhea, rectal bleeding, softer stool, mucus in the stool, tenesmus, and abdominal pain.<ref name=":5" /> The symptoms may continue for around 6 weeks or even longer.

The inflammatory bowel diseases could be effectively treated by 'pharmacotherapies' to relieve and maintain the symptoms, which showed in 'mucosal healing' and symptoms elimination.<ref name=":7">{{Cite journal|last1=Jeong|first1=Dong Yeon|last2=Kim|first2=Seung|last3=Son|first3=Min Ji|last4=Son|first4=Chei Yun|last5=Kim|first5=Jong Yeob|last6=Kronbichler|first6=Andreas|last7=Lee|first7=Keum Hwa|last8=Shin|first8=Jae II|date=May 2019|title=Induction and maintenance treatment of inflammatory bowel disease: A comprehensive review|journal=Autoimmunity Reviews|volume=18|issue=5|pages=439–454|doi=10.1016/j.autrev.2019.03.002|pmid=30844556|s2cid=73466469}}</ref> However, an optimal therapy for curing both inflammatory diseases are still under research due to the heterogeneity in clinical feature.<ref name=":7" /> Although both UC and CD are sharing similar symptoms, the medical treatment of them are distinctively different.<ref name=":7" /> Dietary treatment can benefit for curing CD by increase the dietary zinc and fish intake, which is related to mucosal healing of the bowel.<ref name=":3" /> Treatments vary from drug treatment to surgery based on the active level of the CD. UC can also be relieved by using immunosuppressive therapy for mild to moderate disease level and application of biological agents for severe cases.<ref name=":5" />

===Irritable bowel syndrome===
{{main|Irritable bowel syndrome}}
Irritable bowel syndrome is diagnosed as an intestinal disorder with chronic abdominal pain and inconsistency in form of stool, and is a common bowel disease that can be easily diagnosed in modern society.<ref name=":4">{{cite book |doi=10.1016/B978-0-323-54731-4.00076-1 |chapter=Irritable Bowel Syndrome |title=Atlas of Common Pain Syndromes |year=2019 |last1=Waldman |first1=Steven D. |pages=294–297 |isbn=978-0-323-54731-4 |s2cid=239092846 }}</ref> The variation in incident rate can be explained by different diagnostic criteria in different countries, with the 18–34 age group being recognized as the high frequency incident group.<ref name=":4" /> The definite cause of irritable bowel syndrome remains a mystery; however, it has been found to relate to multiple factors, such as 'alternation of mood and pressure, sleep disorders, food triggers, changing of dysbiosis and even sexual dysfunction'.<ref name=":4" /> One third of irritable bowel syndrome patients has family history with the disease suggesting that genetic predisposition could be a significant cause for irritable bowel syndrome.<ref name=":6">{{Cite journal|last1=Farmer|first1=Adam D|last2=Ruffle|first2=James K|date=May 2019|title=Irritable bowel syndrome|journal=Medicine|volume=47|issue=6|pages=350–353|doi=10.1016/j.mpmed.2019.03.009|pmid=27159638|pmc=5001845}}</ref>

Patients with irritable bowel syndrome commonly experience abdominal pain, changes to stool form, recurrent abdominal bloating and gas,<ref name=":6" /> co-morbid disorders and alternation in bowel habits that caused diarrhea or constipation.<ref name=":4" /> However, anxiety and tension can also be detected, although patients with irritable bowel disease seem healthy. Apart from these typical symptoms, rectal bleeding, unexpected weight loss and increased inflammatory markers require further medical examination and investigation.<ref name=":4" />

Treatment for irritable bowel disease is multimodal. Dietary intervention and pharmacotherapies can both relieve the symptoms to a certain degree. Avoiding allergic food groups can be beneficial by reducing fermentation in the digestive tract and gas production, hence effectively alleviating abdominal pain and bloating.<ref name=":4" /> Drug interventions, such as laxatives, loperamide,<ref name=":4" /> and lubiprostone<ref name=":6" /> are applied to relieve intense symptoms including diarrhea, abdominal pain and constipation. Psychological treatment, dietary supplements<ref name=":4" /> and gut-focused hypnotherapy<ref name=":6" /> are recommended for targeting depression, mood disorders and sleep disturbance.

=== Bowel obstruction ===
{{main|Bowel obstruction}}
Bowel obstruction is a bowel condition which is a blockage that can be found in both the small intestines and large intestines. Increase of contractions can relieve blockages; however, continuous contractions with decreasing functionality may lead to terminated mobility of the small intestines, which then forms the obstruction. At the same time, the lack of contractility encourages liquid and gas accumulation.<ref name=":14">{{Cite journal|last1=Long|first1=Brit|last2=Robertson|first2=Jennifer|last3=Koyfman|first3=Alex|date=February 2019|title=Emergency Medicine Evaluation and Management of Small Bowel Obstruction: Evidence-Based Recommendations|journal=The Journal of Emergency Medicine|volume=56|issue=2|pages=166–176|doi=10.1016/j.jemermed.2018.10.024|pmid=30527563|s2cid=54480601}}</ref> and "electrolyte disturbances".<ref name=":15">{{cite book |doi=10.1016/B978-0-323-40232-3.00072-8 |chapter=Small Bowel Obstruction |title=Shackelford's Surgery of the Alimentary Tract, 2 Volume Set |year=2019 |last1=Johnston |first1=Lily E. |last2=Hanks |first2=John B. |pages=842–850 |isbn=978-0-323-40232-3 |s2cid=81585148 }}</ref> Small bowel obstruction can result in severe renal damage and hypovolemia.<ref name=":15" /> while evolving into "mucosal ischemia and perforation".<ref name=":14" /> Patients with small bowel obstruction were found to experience constipation, strangulation and abdominal pain and vomiting.<ref name=":14" /> Surgical intervention is primarily used to cure severe small bowel obstruction condition. Nonoperative therapy included nasogastric tube decompression, water-soluble-contrast medium process or symptomatic management can be applied to treat less severe symptoms<ref name=":14" />

According to research, large bowel obstruction is less common than small bowel obstruction, but is still associated with a high mortality rate.<ref name=":16">{{cite journal |last1=Farkas |first1=Nicholas G. |last2=Welman |first2=Ted Joseph P. |last3=Ross |first3=Talisa |last4=Brown |first4=Sarah |last5=Smith |first5=Jason J. |last6=Pawa |first6=Nikhil |title=Unusual causes of large bowel obstruction |journal=Current Problems in Surgery |date=February 2019 |volume=56 |issue=2 |pages=49–90 |doi=10.1067/j.cpsurg.2018.12.001 |pmid=30777150 |s2cid=59277670 }}</ref> Large bowel obstruction, also known as colonic obstruction, includes acute colonic obstruction, where a blockage is formed in the colon. Colonic obstructions frequently occur within the elder population, often accompanied by significant 'comorbidities'.<ref>{{Cite journal|last1=Frago|first1=Ricardo|last2=Ramirez|first2=Elena|last3=Millan|first3=Monica|last4=Kreisler|first4=Esther|last5=Valle|first5=Emilio del|last6=Biondo|first6=Sebastiano|date=January 2014|title=Current management of acute malignant large bowel obstruction: a systematic review|journal=The American Journal of Surgery|volume=207|issue=1|pages=127–138|doi=10.1016/j.amjsurg.2013.07.027|pmid=24124659}}</ref> Although colonic malignancy is revealed as the major cause of the colonic obstruction, volvulus has also been founded as a secondary common cause around the world.<ref name=":16" /> In addition, lower mobility, unhealthy mentality and restricted living environment are also listed as risk factors. Surgery and colonic stent placements are widely applied for curing colonic obstructions.<ref>{{Cite journal|last1=Laboa|first1=Maria Navajas|last2=Calzada|first2=Aitor Orive|last3=Landaluce|first3=Aitor|last4=Estevez|first4=Inaki Zabalza|last5=Larena|first5=Jose Alejandro|last6=Arevalo-Serna|first6=Juan Antonio|last7=Bridet|first7=Lionel|last8=Lopez-Lopez|first8=Maria|last9=Burgos|first9=Soraya Torres|date=March 2015|title=Colonic obstruction caused by endometriosis solved with a colonic stent as a bridge to surgery|journal=Arab Journal of Gastroenterology|volume=16|issue=1|pages=33–35|doi=10.1016/j.ajg.2014.10.004|pmid=25791032}}</ref>

===Other===
Attempting forced expiration of breath against a closed airway (the [[Valsalva maneuver]]) is sometimes practiced to induce defecation while on a [[toilet]]. This contraction of expiratory [[chest]] muscles, [[diaphragm (anatomy)|diaphragm]], abdominal wall muscles, and [[pelvis|pelvic]] diaphragm exerts pressure on the digestive tract. [[Ventilation (physiology)|Ventilation]] at this point temporarily ceases as the lungs push the chest diaphragm down to exert the pressure. [[Cardiac arrest]]<ref name="pmid27716918">{{cite journal|vauthors=Fisher-Hubbard AO, Kesha K, Diaz F, Njiwaji C, Chi P, Schmidt CJ|year=2016|title=Commode Cardia-Death by Valsalva Maneuver: A Case Series|journal=[[Journal of Forensic Sciences]]|volume=61|issue=6|pages=1541–1545|doi=10.1111/1556-4029.13196|pmid=27716918|s2cid=4727369|hdl=2027.42/134829|hdl-access=free}}</ref> and other cardiovascular complications<ref name="pmid27151226">{{cite journal|vauthors=Ikeda T, Oomura M, Sato C, Anan C, Yamada K, Kamimoto K|year=2016|title=Cerebral infarction due to cardiac myxoma developed with the loss of consciousness immediately after defecation-a case report|journal=Rinsho Shinkeigaku|volume=56|issue=5|pages=328–333|doi=10.5692/clinicalneurol.cn-000856|pmid=27151226|doi-access=free}}</ref> can in rare cases occur due to attempting to defecate using the Valsalva maneuver. [[Valsalva retinopathy]] is another pathological syndrome associated with the Valsalva maneuver.<ref>{{cite journal|last1=Gibran|first1=S K|last2=Kenawy|first2=N|last3=Wong|first3=D|last4=Hiscott|first4=P|year=2007|title=Changes in the retinal inner limiting membrane associated with Valsalva retinopathy|journal=[[British Journal of Ophthalmology]]|volume=91|issue=5|pages=701–2|doi=10.1136/bjo.2006.104935|pmc=1954736|pmid=17446519}}</ref><ref name="pmid19747224">{{cite journal|author=Connor AJ|year=2010|title=Valsalva-related retinal venous dilation caused by defaecation|journal=[[Acta Ophthalmologica]]|volume=88|issue=4|pages=328–33|doi=10.1111/j.1755-3768.2009.01624.x|pmid=19747224|s2cid=26590048|doi-access=free}}</ref> Thoracic [[blood pressure]] rises and as a reflex response the amount of blood pumped by the heart decreases. Death has been known to occur in cases where defecation causes the blood pressure to rise enough to cause the rupture of an [[aneurysm]] or to dislodge blood clots (see [[thrombosis]]). Also, in releasing the Valsalva maneuver blood pressure falls; this, coupled with standing up quickly to leave the toilet, can result in a blackout.{{citation needed|date=February 2013}}
[[File:Hurkende man Capricci di varie Figure di Jacopo Callot (serietitel) Diverse figuren en voorstellingen (serietitel), RP-P-OB-21.068.jpg|thumb|right|280px|A person defacating outside. Etching, paper. Jacques Callot. Rijksmuseum,  Amsterdam. 1621]]