Sm Intestine Colon Path- Nelson Flashcards
What are the major differences between ulcerative colitis and crohn’s disease?
UC:
- inflammation of mucosa (maybe submucosa- NOT transmural)
- Involves rectum and maybe colon
- Continuous
Crohns:
- transmural inflammation
- Can involve anywhere in the GI tract
- Skip lesions
What is inflammatory bowel disease?
Inappropriate mucosal immune reaction to luminal bacteria (in genetically susceptible individuals!)
Most common cause of acute diarrhea?
Infectious diarrhea!!!
How do you diagnosis clostridium Difficile?
Stool PCR assay to look for toxin-producing strains
What type of colitis is associated with C. diff?
psuedomembrane colitis - mucosal surface EXUDATE of necrotic epithelial cells, neutrophils, mucin, and fibrin
For indeterminate colitis, how would would one distinguish UC from CD?
Serologic studies!
CD = ASCA positive UC = pANCA positive
Name some gross features of crohn’s disease?
Transmural inflammation:
Cobblestone mucosa
Creeping Fat
Bowel wall thickening
Gross morphology of ulcerative colitis?
Mucosal and submucosal inflammation only:
Psuedopolyps!
Non-caseating granulomas is associated with which inflammatory bowel disease?
CROHNS!
What is a long term complication of both CD and UC?
Development of intestinal adenocarcinoma
Diversion colitis
- Colitis in a blind distal segment of the colon (excluded from fecal stream)
- Following surgery that made a diverting ostomy
- Due to deficiency of short-chain fatty acids (normally produced from fermentation of dietary starches by normal colonic bacterial flora)
- These starches are absent in the diverted segment, due to changes in the luminal microbiota and diversion of the normal fecal stream
Clinical presentation for microscopic colitis?
Chronic watery diarrhea
NORMAL colonoscopic exam
Two types of microscopic colitis?
- Lymphocytic colitis
- Collagenous colitis
Lymphocytic colitis
- Increased lamina propria chronic inflammation
- Increased intra-epithelial lymphocytes
- Surface epithelial damage
Collagenous colitis
Band of sub-epithelial collagen is seen in addition to inflammatory changes
Radiation enterocolitis
Occurs when GI tract is irradiated
Can be acute or chronic
Can develop ulcers, strictures, fistula, serosal adhesions
Neonatal necrotizing enterocolitis
First week of life in premature infants
Small and large bowel with transmural necrosis
What class of drugs is commonly implicated in drug-induced enterocolitis?
NSAIDS!
Chronic, replapsing abdominal pain or discomfort
Bloating
Changes in bowel habits (diarrhea or constipation)
Absence of any known causative agent that could explain symptoms
Irritable bowel sydnrome
Irritable bowel syndrome is most common in which population?
Middle-aged women!
List some causes of ischemic bowel disease
Acute arterial obstruction/thrombosis = atherosclerosis, aortic aneurysm, etc
Mesenteric venous thrombosis = portal hypertension, trauma, neoplasms, etc.
Hypoperfusion = cardiac failure, shock, vasoconstrictive drugs, etc.
What are the bowel segments most likely to be affected by ischemia?
Splenic flexure (SMA and IMA watershed zone)
Sigmoid Colon
Rectum (IMA, pudendal artery, iliac artery watershed zone)
Complication of transmural bowel necrosis?
Sepsis due to break down of mucosal barriers (w/ septic shock/death)
What is angiodysplasia?
malformed submucosal and mucosal blood vessels
