Colitis Flashcards
What is the most frequent form of intestinal ischemia? who has the highest risk?
Ischemic Colitis
highest risk = pts w recent cardiovascular surgery
How does ischemic injury to the colon usually occur? how is this aggravated?
hypoperfusion to the intramural vessels of the colon MUCOSAL wall (rarely transmural)
aggravated by chronic atherosclerosis/vasculitis
What two areas of the colon are most at risk for ischemia? What area is usually spared?
Watershed areas:
- Splenic flexure
- Left colon (rectro sigmoid jxn)
rectum is usually spare (dual blood supply)
What is the clinical presentation of colonic ischemia
Sudden-onset of severe crampy left lower quadrant abdominal pain
followed shortly after w Hematochezia*
AFEBRILE
What are complications of Ischemic colitis
Colon gangrene
bowel perforation
Chronic Segmental Ulcerating Colitis
Colonic strictures
What does Ischemic Colitis look like on abdominal xray?
“thumbprinting” = thickening of the colon wall caused by intramural hemorrhage
What does Ischmic Colitis look like on CT?
Double Halo Sign - bowel wall thickening
What does colonoscopy look like in Ischemic Colitis?
Submucosal hemorrhage, ulceration or necrosis
Segmental distribution of ischemia
What is the Tx for Ischemic Colitis?
Most pts: Sx resolve within 24-48 hrs
Tx: IVF’s, bowel rest
What is the endoscopic appearance of crohn’s colitis?
Rake ulcers - deep, linear
Aphthous ulcers
Cobblestone appearance
rectal sparing
What are the Dx serum markers for IBD:
- UC
- CD
- pANCA
2. ASCA
What are general histological findings in IBD?
- acute inflammation:
neutrophilis cryptitis - chronic inflammation:
Crypt distortion, plasmacytic infiltration of the lamina propria
What is Microscopic Colitis?
Chronic diarrhea w. voluminous, watery, nonbloody diarrhea in pts with NORMAL endoscopic appearance but biopsies have histological evidence of inflammation
What are the two histologic types of microscopic colitis? what are characteristics
Lymphocytic
Collagenous - subepithelial collagen deposition
-both have lymphocytic infiltration of the colonic epithelium
Who does Microscopic Colitis affect the most? What is it associated with?
Female 10:1
a/w autoimmune diseases
induced by NSAIDS
What are symptoms and signs of Microscopic Colitis?
- Watery diarrhea 5-10 times a day
- Nocturnal diarrhea
- chronic/intermittent
- Normal physical exams and labs
What are the Dx histologic findings in Lymphocytic colitis and Collagenous colitis
LC: excess of intraepithelial lymphocytes, inflammation of the lamina propria w plasma cells, eosinophils, mast cells
CC: band of eosinophilic deposite under epithelium (type III collagen and fibronectin), inflammation of lamina propria
What are the treatments of Microscopic Colitis (Mild, Moderate, Severe)
first: stop associated meds: NSAIDs
mild - Loperamide
moderate - Bismuth
Severe - Budesonide
What is Radiation Colitis and what are Sx?
Acute/Chronic damage to normal colon and rectum after radiation treatment Sx: 1. acute self-limiting diarrhea 2. tenesmus 3. abdominal cramping 4. bleeding (rare)
happens b/c of damage to epithelial lining with sloughing of mucosa
What does sigmoidoscopy show in Radiation colitis?
telangiectasia
inflammation
ulcers
strictures
What is Tx of radiation colitis?
Cautery of telangiectasia (stop bleeding)
Steroid/Sucralfate enemas
iron supplement
What is a major cause of hospital acquired diarrhea? what are its characteristics?
Clostridium difficile (Pseudomembranous colitis)
Gram +
heat/alcohol resistant
spore forming
anaerobic bacillus
What does C. diff produce that causes diarrhea? what is the action of this product?
enterotoxin A and B
binds epithelium = inflammatory reaction
produces protein rich exudates w neutrophils, enterocytes = PSEUDOMEMBRANE
What are the 3 antibiotics implicated in causing C. diffi infections?
Clindamycin - 15%
Aminopenicillins - 35%
Cephalosporins - 30%
