Editing Colitis (section)

==Diagnosis==
Symptoms suggestive of colitis are worked-up by obtaining the [[medical history]], a physical examination and laboratory tests ([[complete blood count|CBC]], [[serum electrolytes|electrolytes]], stool culture and sensitivity, stool ova and parasites et cetera).  Additional tests may include medical imaging (e.g. abdominal [[computed tomography]], [[abdominal X-ray]]s) and an examination with a camera inserted into the rectum ([[sigmoidoscopy]], [[colonoscopy]]).<ref>{{Cite web |title=Diagnosis of Ulcerative Colitis {{!}} NIDDK |url=https://www.niddk.nih.gov/health-information/digestive-diseases/ulcerative-colitis/diagnosis |access-date=2022-11-18 |website=National Institute of Diabetes and Digestive and Kidney Diseases |language=en-US}}</ref>

An important investigation in the assessment of colitis is biopsy for [[histopathology]]. A very small piece of tissue (usually about 2mm) is removed from the bowel mucosa during endoscopy and examined under the microscope by a histopathologist. A biopsy report generally does not state the diagnosis, but should state any presence of chronic colitis, give an indication of disease activity, as well as state the presence of any epithelial damage (erosions and ulcerations).<ref name=Kellermann2021>{{cite journal|author=Kellermann L, Riis LB.|title=A close view on histopathological changes in inflammatory bowel disease, a narrative review.|journal=Dig Med Res|year=2021|volume=4|issue=3|page=3|doi=10.21037/dmr-21-1|doi-access=free|url=https://dmr.amegroups.org/article/view/7171/html|access-date=2023-10-03|archive-date=2024-01-23|archive-url=https://web.archive.org/web/20240123054132/https://dmr.amegroups.org/article/view/7171/html|url-status=live}}</ref>

Histopathology findings generally associated with chronic colitis include:<ref name=Kellermann2021/>
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File:Histopathology of a degenerated crypt of chronic inactive colitis.jpg|Crypt degeneration
File:Histopathology of crypt branching of colon.jpg|Crypt branching and other architectural distortions
File:Histopathology Paneth cell metaplasia.jpg|[[Paneth cell]] (pictured) or gastric metaplasia (only applies in the left colon and rectum)
</gallery>
Other findings include basal plasmacytosis and mucin depletion.<ref name=Kellermann2021/>
Histopathology findings generally associated with active colitis include:<ref name=Kellermann2021/>
<gallery mode=packed heights=110>
File:Histopathology of neutrophilic cryptitis in active colitis, annotated.jpg|Neutrophilic cryptitis (neutrophils within crypt epithelium)
File:Histopathology of a crypt abscess.jpg|Crypt abscesses (luminal neutrophilic aggregates)
File:Histopathology of gland destruction in active colitis.jpg|Gland destruction
File:Histopathology of colonic ulceration.jpg|Ulceration (seen here as absence of epithelium, and granulation tissue with many fibroblasts)
</gallery>