Small Bowel and Appendix Flashcards
Tumors of the appendix
About 1/2= carcinoid (neuroendocrine tumor), mets to liver can produce serotonin syndrome (episodic flushing, diarrhea, wheezing and right sided valvular heart disease)
-Mets rare if tumor pseudomyxoma peritonei charac by diffuse collections of gelatinous material thru the abdomen
Appendicitis
- mid abdominal pain that migrates to the RLQ
- Nausea and vomiting -High fever, WBC count and severe pain suggest perforation.
- IV fluids, IV antibiotics and surgical resection are the treatment.
Plicae circulares
more in prox jejunum, absent terminal ileum
ileum empties into cecum of LI
absorption and transport of fluids
9L secreted/ingested
8.9 L absorbed
100 ml excreted
Malabsorption/maldigestion
- inadequate absorp of nutrients
- Clinical signs: weight loss, diarrhea, steatorrhea, vitamin deficiencies
- Pale, bulky, malodorous stool: float, hard to flush, oily residue
Causes of malabsorption
Surgery: -gastric bypass -small bowel resection Bacterial overgrowth Meds: cholestyramine-ADEK phenytoin, folate Pancreatic insufficiency Liver disease Intestinal inflammation/villous flattening (celiac sprue, Whipple's disease, tropical sprue) Ulceration Ischemia Infiltration (amyloidosis)
What test might you use to dx fat malabsorption?
Sudan fat stain
Pancreatic insufficiency
90% burned out
Lipid (first) then protein then rarely carb malabsorption
-chronic pancreatitis
-CF
Liver disease
bile needed for absorption of lipids
- Cirrhosis (decreased func of hepatocytes, decreased bile formation)
- Biliary obstruction
Gastric Bypass
B-II, Roux-en Y
inadequate mixing of food with biliary and pancreatic secretions
Gastric Bypass Vitamin Deficiencies
B12, Fe, Ca, Vit D deficiencies are the most common
-Vit C, Cu rare
Prevention: multivitamin
Monitoring recommended
Small Bowel Bacterial Overgrowth
Normal:
Vitamin levels with bacterial overgrowth and
Dx
fat soluble vitamins and B12 deficiency (bacteria deconjugate bile salts, bacteria consume B12)
Folate: normal to high (bacterial production)
Dx: -Aspiration of duodenum w/ culture -Glucose-hydrogen breath test -empiric treatment with antibiotics Treatment: antibiotics (eg Ciprofloxacin)
Sx of Vit A def
night blindness
xerophthalmia
Sx of Vit D def
Osteomalacia
-bone mineralization defects
Sx of Vit E def
rare in adults
hemolytic anemia
sx of vit K def
clotting dysfunction
-PT
Celiac Sprue
- gluten sensitive enteropathy (wheat, barley, rye)
- inflammatory disease of small intestine
- loss of villi, crypt hyperplasia, lymphocytes
- 80% asx (0.5-1% of US pop)
- incidence increases with age
Signs/sx of celiac sprue
Abdominal distension Abdominal pain Anorexia Bulky, sticky, pale stools -Steatorrhea Diarrhea Flatulence Failure to thrive -Weight loss -Fatigue Vomiting
Atypical signs/sx of celiac sprue
Iron deficiency Anemia Dermatitis Herpetiformis Liver function tests -AST, ALT elevations Cerebellar ataxia Osteoporosis Oral apthous ulcers
Celiac pathogenesis
-assoc w/ autoimmune diseases: thyroiditis, Type-I DM
-HLA-DQ2, HLA-DQ8 (40% US)
APC MHC II present gluten peptides
CD4+ Tcell response
All have ab to tissue transglutaminase (TTG)
Dx of Celiac sprue
Dx:
- finding on SI biopsy
- Serologic tests: anti-TTG, anti-endomysial antibodies, anti-gliadin IgA and IgG
Tx: gluten free diet
Findings on endoscopy for celiac
scalloped duodenal folds
Tropical sprue
- residents/visitors of tropics
- Cause: bacterial toxins or colonization of aerobic coliform bacteria
Classic presentation: Megaloblastic anemia from B12 and folate deficiency
Diagnosis: intestinal biopsy with villous flattening and travel history
Treatment: Antibiotics, B12, and folate
Whipple’s Disease
RARE (
Mesenteric Ischemia
Atherosclerosis, Clot, Radiation
Chronic: 2 of 3 major vessels occluded
post-prandial abdominal pain, weight loss, sitophobia, malabsorption
Acute: embolus, severe abdominal pain
Malabsorption diagnostic tests
Focused testing-clinical scenario Fecal Fat Vitamin levels CBC, albumin CT-small bowel, liver, pancreas, bile ducts Endoscopy
Small Intestinal Tumors
RARE primary tumors (
Two main causes of diarrhea
decreased fluid/elec absorption
increased secretion
-occurs when colonic water load exceeds absorptive capacity
Diarrhea classification
Fatty
- malabsorption
- maldigestion
Watery
- osmotic
- secretory
Inflammatory/exudative
Functional
Watery diarrhea– osmotic
Carb malabsorption:
lactose
sorbitol (gum)
fructose (non-diet drinks and many commercial foods)
Osmotic laxatives:
- Magnesium containing
- Phosphate, sulfate (colonoscopy bowel preps)
Osmotic diarrhea: presence of OSMOLAR GAP
*ie presence of poorly absorbed luminal osmols
Osmotic vs secretory diarrhea
Osm gap= 290-2(stool sodium + potassium)
diff >50mOsm, diarrhea is osmotic
Lactose intolerance
> 50% of world down-regulates lactase after weaning
–>diarrhea (osmotic), flatulence (colonic bacteria)
Secretory watery diarrhea
Bacterial toxins -V. cholerae, E. coli enterotoxins Neuroendocrine tumors -gastrinoma, VIPoma, carcinoids, calcitonin Ileal bile salt malabsorption Stimulant laxatives Disordered motility/regulation -Diabetic neuropathy, postvagotomy, irritable bowel syndrome
Bile acid induced diarrhea
- from ileal dysfunction (only site of ACTIVE bile acid absorption
- increased bile acid into colon–> colonic secretion of fluid/elec–> diarrhea
Fatty diarrhea
Malabsorption syndromes
-Mucosal diseases (Celiac disease, Whipple’s disease)
-Short-bowel syndrome
-Small bowel bacterial overgrowth
Maldigestion/Malabsorption
-Pancreatic insufficiency
-Inadequate luminal bile salt concentration (chronic liver disease, biliary obstruction)
Inflammatory diarrhea
Infection
Inflammatory Bowel Disease
- Crohn’s Disease
- Ulcerative Colitis
Ischemia
Fecal leukocytes in intestinal infections
Present:
Shigella
Campylobacter
Enterohemorrhagic, enteroinvasis E. coli
Variable:
Salmonella
Yersinia
Clostridium difficile (pseudomembranous colitis)
Absent:
V. cholerae
Enterotoxigenic E. coli
Giardia lamblia
Inflammatory diarrhea dx
Infection:
Usually Stool Culture
Endoscopy
Ischemia:
CT scan
Endoscopy-colon
Inflammatory Bowel Disease:
Endoscopy
IBS
Abdominal Pain and altered bowel habits in the absence of an organic cause:
Pain improved with defecation
Pain onset with change in stool frequency
Pain onset with change in stool appearance
Constipation and/or Diarrhea
10-15% of the population North America
Possible mechanisms: Visceral hypersensitivity Carbohydrate malabsorption -FODMAPS fermentable oligo-, di-, and monosaccharides and polyols (Fructose, fructans (wheat polymers e.g.inulin) sorbitol, lactose,) Low grade inflammation
When to be concerned about IBS
Weight Loss Rectal bleeding Anemia Nocturnal symptoms Electrolyte abnormalities Elevated inflammatory markers
What could be the result of longstanding Celiac?
T cell lymphoma
Arterial supply to SI, LI
SMA: part of duodenum, entire SI, half of colon
IMA: left colon and rectum
Collateral circ bt SMA and IMA via marginal arteries and Arc of Riolan
