GI: 354 - 357 Flashcards
What is thought to be the cause of Crohn disease vs. ulcerative colitis?
Crohn disease - disordered response to intestinal bacteria
Ulcerative colitis - autoimmune
What is the difference in localization of Crohn disease vs. ulcerative colitis?
Crohn disease - any portion of the GI tract; usually the terminal ileum and colon; skip lesions; rectal sparing
Ulcerative colitis - colonic inflammation that is continuous; always has rectal involvement
What do you see on gross morphology with Crohn disease?
Transmural inflammation - fistulas, cobblestone mucosa, creeping fat, bowel wall thickening, linear ulcers, fissures
What do you see on barium swallow with Crohn disease?
String sign - due to wall thickening which narrows the lumen
How is gross morphology of ulcerative colitis different from Crohn disease in terms of the layers affected?
Ulcerative colitis affects mucosa and submucosa vs. Crohn disease which is transmural
Describe what you see on gross morphology with ulcerative colitis.
Friable mucosal pseudopolyps with freely hanging mesentery
What do you see on imaging with ulcerative colitis and why?
Lead pipe appearance with loss of haustra
Contrast Crohn disease and ulcerative colitis in terms of Th1 vs. Th2 response.
Crohn disease - Th1 (noncaseating granulomas and lymphoid aggregates)
Ulcerative colitis - Th2 (crypt abscesses, ulcers, bleeding, no granulomas)
Strictures (leading to obstruction), fistulas, perianal disease, malabsorption, nutritional depletion, colorectal cancer, gallstones - complications of Crohn or ulcerative colitis?
Crohn
Malnutrition, sclerosing cholangitis, toxic megacolon, colorectal cancer - complications of Crohn or ulcerative colitis?
Ulcerative colitis
When do you have an increased risk of colorectal cancer with ulcerative colitis?
Worse with right-sided colitis or pancolitis
Is bloody diarrhea more common with Crohn disease or ulcerative colitis?
Ulcerative colitis
Compare and contrast the extraintestinal manifestations of Crohn disease vs. ulcerative colitis.
Both - erythema nodosum, uveitis, aphthous ulcers, ankylosing spondylitis, pyoderma gangrenosum
Crohn only - migratory polyarthritis, kidney stones
Ulcerative colitis only - primary sclerosing cholangitis
How do we treat Crohn disease?
Corticosteroids, azathioprine, methotrexate, infliximab, adalimumab
How do we treat ulcerative colitis?
ASA preparations (sulfasalazine), 6-mercaptopurine, infliximab, colectomy
How do we define irritable bowel syndrome?
Recurrent abdominal pain associated with at least 2 of the following:
- Pain improves with defecation
- Change in stool frequency
- Change in appearance of stool
What are the structural abnormalities with irritable bowel syndrome?
None
Is irritable bowel syndrome more of an acute or chronic disease?
Chronic
What demographic does irritable bowel syndrome tend to affect?
Middle aged women
How does IBS tend to present?
Diarrhea, constipation, or alternating symptoms
How do we treat IBS?
Symptomatic management
Contrast the causes of appendicitis in children vs. adults.
Children - lymphoid hyperplasia
Adults - obstruction by fecalith
How does appendicitis present?
Initial diffuse periumbilical pain that migrates to McBurney point
Where is McBurney point?
Half the distance between anterior superior iliac spine to umbilicus
If an appendicitis patients has fever and nausea, what should you be concerned about?
Possible perforation
What might you see with perforation of the appendix?
Psoas, obturator, and Rovsing signs
What should be on your differential with appendicitis?
Diverticulitis (elderly), ectopic pregnancy (beta-hCG to rule out)
How do you treat appendicitis?
Appendectomy
What is the difference between a true vs. false diverticulum?
True diverticulum - all 3 gut wall layers outpouch (e.g. Meckel)
