Editing Defecation (section)

=== 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" />