Editing Ulcerative colitis (section)

== '''Investigations''' ==

* Check for inflammatory and nutritional markers
** Albumin, Hb, iron
* Serologic markers
** Antibodies against Saccharomyces cerevisiae (ASCA) - positive in 35-50% of Crohn's, and <1% of UC

** Perinuclear antineutrophilic cytoplasmic antibodies (p-ANCA)
*** (Helpful in differentiating Crohn's and UC - ASCA positive, p-ANCA negative suggests CD, whereas p-ANCA is more likely to be elevated in UC)

* Stool MCS + CDT
* ALP may be elevated in PSC
* AXR:
** Patients with severe disease may show proximal constipation, mucosal thickening/'thumbprinting', colonic dilatation
* Barium enema
** Avoid in unwell patients - may precipitate ileus with toxic megacolon
* CT and MRI
** May demonstrate marked thickening of the bowel wall - non-specific
** Lower sensitivity than barium enema for the detection of subtle early mucosal disease
* Endoscopy
** Use Mayo Clinic Scoring System to grade
** Inflammation involving rectum and extending proximally in a continuous and circumferential pattern with a sharp cut-off between involve and uninvolved mucosa
** Can also have a 'caecal patch' of inflammation around the appendiceal orifice which is non-continuous with other areas of inflammation
** Backwash ileitis may be seen in patients with UC with active right-sided colitis - typically diffuse, rather than the patchy inflammation seen in CD ileum
** Loss of vascular markings due to engorgement of the mucosa
** Petechiae
** Exudates
** Oedema
** Erosions
** Touch friability/spontaneous bleeding
** Non-neoplastic pseudo-polyps

***

** Severe: macro-ulcerations, profuse bleeding, copious exudates
**

* Biopsies of bowel
** Nothing fully specific for UC, but presence of two or more features is suggestive
*** '''Crypt abscesses'''; crypt branching, shortening and disarray; and crypt atrophy
*** Epithelial cell abnormalities - '''goblet cell/mucin depletion''' and Paneth cell metaplasia
*** '''Increased lamina propria cellularity''' (polymorphonuclear leucocytes), basal plasmacytosis, basal lymphoid aggregates, and lamina propria eosinophils
** Absence of mural sinus tracts, deep fissural ulcers, and granulomas, as well as by the absence of transmural lymphoid aggregates in an area not deeply ulcerated