Section 2: IBD, Diarrhea, Malabsorption and Colon Cancer Flashcards
Inflammatory Bowel Disease (IBD):
- Made up of?
- Clinical features of IBD
- Extraintestinal manifestations of IBD
- Crohn’s disease and ulcerative colitis
- Fever, abdominal pain, diarrhea, blood in the stool, and weight loss
- Joint pains; Eye findings (iritis, uveitis); Skin findings (pyoderma granulosum, erythema nodosum); Sclerosing cholangitis
Features more common to Crohn’s disease
- Masses
- Skip lesions
- Upper GI involvement
- Perianal disease
- Transmural granulomas
- Fistulae
- Hypocalcemia from fat malabsorption
- Obstruction
- Calcuim oxalate kidney stones
- Cholesterol gallstones
- Vitamin B12 malabsorption from terminal ileum involvement
Use “SOFT MUPS”
- S=Skip lesions
- O=Obstruction
- F=Fistulas
- T=Transmural
- M=Masses; Malabsorption (of Vit B12)
- U=Upper GI; Uveitis
- P=Perianal
- S=Stones(Cholesterol gallstones and Calcium oxalate kidney stones)
IBD:
- Diagnostic testing
- Endoscopy
- Barium studies
- Crohn’s disease: ASCA +, ANCA -
- Ulcerative colitis: ASCA -, ANCA +
ASCA: Antisaccharomyces cerevesiae antibody
ANCA: Antineutrophil cytoplasmic antibody
Remember, ASCA has cerevesiae as Crohn’s
Treatment of Crohn’s Disease
- Mild Disease
- Moderate Dz
- Refractory Dz
- Follow up
- Mild Dz: 5-ASA (mesalamine)
- Oral Glucocorticoids
+/- Azathioprine
6-mercaptopurine
or methotrexate - IV steroids +/- anti-TNF
- Colonoscopy w/biopsies 8-10 years after diagnosis then 1-2 times a year after that
Treatment of Ulcerative Colitis
- Mild Disease
- Moderate Dz (toxic megacolon)q
- Refractory Dz
- Follow up:
- What do some pts prefer?
- Mild Dz: 5-ASA (mesalamine)
- Oral Glucocorticoids
+/- Azathrioprine
6-mercaptopurine
or methotrexate - IV steroids +/- anti-TNF
- Colonoscopy w/biopsies 8-10 years after diagnosis then 1-2 times a year after that
- Prophylactic Colectomy
List the causes of fat malabsorption
- Celiac disease (gluten sensitive enteropathy) or nontropical sprue
- Tropical sprue
- Chronic pancreatitis
- Whipple’s disease
Clinical features of malabsorption syndrome
- Hypocalcemia → osteoporosis
- Oxalate overabsorption and oxalate kidney stones
- Easy bruising and elevated prothrombin time/INR
- Vitamin B12 malabsorption
Malabsorption
- Best initial test
- Most sensitive test
- Sudan black stain of stool
- 72-hour fecal fat
CF of Celiac disease (Gluten-sensitive enteropathy)
- Malabsorption of iron
- Microcytic anemia
- Folate malabsorption
- Dermatitis herpetiformis
Celiac disease:
- Best initial test
- Most accurate test
- Why is bowel biopsy always necessary in celiac disease
- Rx
- Best initial test: Antigliadin, antiendomysial, and antitissue transglutaminase antibodies
- Most accurate test: Small bowel biopsy
- Bowel biopsy is always necessary for celiac disease, even if the diagnosis is confirmed with antibody testing, to exclude bowel wall lymphoma
- Eliminate wheat, oats, rye, and barley from the diet. Use the mnemonic “BROW”
D-xylose testing is abnormal in celiac disease, Whipple disease, and tropical sprue, because the villous lining is destroyed and D-xylose cannot be absorbed. However, this test is rarely necessary, because the specific antibody tests eliminate the need for it
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 6136-6141). . Kindle Edition.
Whipple’s Disease:
- Additional CFM
- Most accurate test
- An alternate test
- Rx
- arthralgia; neurologic abnormalities; ocular findings
- Small bowel biopsy showing PAS positive organisms
- PCR of the stool for Trophyrema whippelei
- Tetracycline or TMP/SMX
CF of IBS
- Abdominal pain relieved by a bowel movement
- Abdominal pain that is less at night
- Abdominal pain with diarrhea alternating with constipation
Irritable bowel syndrome presents with pain. There is no fever, no weight loss, and no blood in the stool.
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 6178-6181). . Kindle Edition.
Diagnostic tests for IBS
All diagnstic tests will be normal.
For the CCS do:
- Stool guaiac, stool white cells, culture, ova, and parasite exam
- Colonoscopy
- Abdominal CT scan
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 6184-6189). . Kindle Edition.
Rx for IBS
Best initial therapy: Fiber. Bulking up the stool helps relieve the pain. Fiber gives the guts a stretch, like sending the colon to yoga class!
If there is no relief of pain with fiber, then you fiber, then you should add antispasmodic/ anticholinergic agents, such as dicyclomine or hyoscyamine, which “relax” the bowel.
If there is no response to the antispasmodic/ anticholinergic agents, you should add a tricyclic antidepressant, such as amitriptyline. Tricyclic antidepressants help IBS because they
– are anticholinergic;
– relieve neuropathic pain;
and – are antidepressant.
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 6188-6197). . Kindle Edition.
Recommendation for colon cancer screening:
- General Population
- Single Family Member with Colon Cancer
- Three Family Members, Two Generations, One < 50
- Familial Adenomatous Polyposis
- Gardner’s, Peutz-Jeghers, Juvenile Polyposis, Turcot’s Syndrome
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 6251-6265). . Kindle Edition.
- Start screening at age 50. Colonoscopy every 10 years.
- Start screening at age 40 or 10 years earlier than the age at which the family member contracted cancer.
- Colonoscopy every 1– 2 years starting at age 25.
- Sigmoidoscopy every 1– 2 years starting at age 12.
- No extra screening recommendations.
Fischer, Conrad (2012-09-22). Master the Boards: USMLE Step 3 (Kindle Locations 6251-6265). . Kindle Edition.
