Disorders of the Small Bowel Flashcards
Technical definition of diarrhea?
> 200 grams of dry stool and change in stool consistency
Technical definition of diarrhea?
> 200 grams of dry stool and change in stool consistency
Definition of acute diarrhea?
Most common cause of acute diarrhea?
Viral gastroenteritis. Self-limited.
Two categories of acute diarrhea?
Enterotoxic and invasive
Common pathogens of enterotoxic acute diarrhea?
C. Diff Enterotoxic E.coli Vibrio cholerae Staph Aureus Bacillus Cereus Giardia
C. diff association?
Recent abx/hospitalization.
Enterotoxic E. Coli association?
traveler’s diarrhea, central america
V. cholera association?
fecal oral, contaminated water, 3rd world
Staph aureus association?
Proteinaceous foods - egg salad, potato salad, etc.
Giardia association?
freshwater. (camping, etc).
Giardia association?
freshwater. (camping, etc).
What are the most common pathogens of invasive diarrhea?
Salmonella, Shigella, EHEC E. Coli, Campylobacter, E. Histolytica
Most common cause of acute diarrhea?
Viral gastroenteritis. Self-limited.
Two categories of acute diarrhea?
Enterotoxic and invasive
Common pathogens of enterotoxic acute diarrhea?
C. Diff Enterotoxic E.coli Vibrio cholerae Staph Aureus Bacillus Cereus Giardia
Association of E. Histolytica?
HIV/AIDs/immunocompromised
Enterotoxic E. Coli association?
traveler’s diarrhea, central america
Presentation of invasive acute diarrhea?
Bloody diarrhea, fever, elevated WBCs, fecal white blood cells, lactoferrin
Staph aureus association?
Proteinaceous foods - egg salad, potato salad, etc.
B. Cereus association?
Reheated rice.
Treatment of C. Diff?
Oral metronidazole, Oral vanc, or, if very very sick, PO vanc + IV metronidazole.
Presentation of enterotoxic acute diarrhea?
Absorptive/secretory, watery non-bloody diarrhea. Usually no fever or WBCs or fecal leuks.
What would colonoscopy show in C. diff?
“psuedomembranous” colitis.
Association of salmonella?
Raw chicken/eggs
Association of shigella?
hemolytic uremic syndrome - thrombocytopenia, thrombotic purpura.
Association of EHEC E. Coli
uncooked red meat
What do you do with refractory C. Diff?
fecal TX
What is the supportive treatment of diarrhea?
Oral fluids, electrolyte replacement as needed, antidiarrheals such as loperamide and bismuth salicylate.
If infection is suspected, what is the treatment of acute diarrhea?
Abx - no antimotility agents.
Common cause of pediatric diarrhea?
Rotavirus infection (winter).
What is the definition of chronic diarrhea?
> 6 weeks, usually not infectious.
Treatment of C. Diff?
Oral metronidazole, Oral vanc, or, if very very sick, PO vanc + IV metronidazole
Under what circumstances would you treat c. diff with PO vanc and IV metronidazole?
Fever, leuks, megacolon, elev BUN/Cr.
What would colonoscopy show in C. diff?
“psuedomembranous” colitis.
What are you looking for in stool studies for acute diarrhea?
WBCs, RBCs in stool –> if yes, stool culture for infectious source
With osmotic diarrhea that is neg for fecal fat, what are some etiologies?
lactose intolerance
Sorbitol, lactulose
Laxative abuse
What does a normal or low osmotic gap mean?
Electrolytes are high causing a low gap.
What do you do with refractory C. Diff?
fecal TX
What is the supportive treatment of diarrhea?
Oral fluids, electrolyte replacement as needed, antidiarrheals such as loperamide and bismuth salicylate.
If infection is suspected, what is the treatment of acute diarrhea?
Abx - no antimotility agents.
Common cause of pediatric diarrhea?
Rotavirus infection (winter).
What is the definition of chronic diarrhea?
> 6 weeks, usually not infectious.
What is the osmolar gap?
Gap = Measured osms - Calculated Osms
= 290 - 2 (Na+K).
What does a high osmolar gap mean?
Low electrolytes, >100 = osmotic diarrhea; caused by something in the GI tract that can’t be absorbed, causes diarrhea.
With known osmotic chronic diarrhea, what step can you take next?
Check fecal fat
With osmotic diarrhea that is + for fecal fat, what are some etiologies?
Malabsorption syndromes, pancreatic insufficiency, bacterial overgrowth
Treatment of carcinoid tumor?
CT C/A to stage, octreotide for sx, resection of tumor.
If fecal RBCs + WBCs present in chronic diarrhea then what?
Colonoscopy to eval for IBD or cancer.
Irritable bowel syndrome?
“Functional” disorder associated with abdominal pain and changes in bowel habits that increase w/ stress and are relieved by a bowel movement.
Treatment of IBS?
Reassurance. Maybe TCAs, fiber supplements, antidiarrheals. Tegaserod for constipation-predominant IBS.
Test for Zollinger-Ellison syndrome?
Gastrin level, if between 250-1600, secretin stim test. If below 250, not ZE, if above 1600, def ZE.
treatment for ZE syndrome?
resection
What is a carcinoid tumor?
Tumor that secretes serotonin and substance P. From enterochromaffin cells.
When is a carcinoid tumor evident?
When it mets to the liver and therefore serotonin gets dumped into circulation w/out being processed.
What does carcinoid tumor of the GI tract cause?
Flushing, diarrhea, wheezing, fibrosis and valve issues with the RIGHT side of heart, as the lung will break down.
What does carcinoid tumor in the lung cuase?
fibrosis of hte LEFT side of the heart, + flushing, diarrhea, wheezing, etc.
Diagnosis of carcinoid tumor?
Urine 5-HIAA.
Treatment of carcinoid tumor?
CT C/A to stage, octreotide for sx, resection of tumor.
If fecal RBCs + WBCs present in chronic diarrhea then what?
Colonoscopy to eval for IBD or cancer.
Irritable bowel syndrome?
“Functional” disorder associated with abdominal pain and changes in bowel habits that increase w/ stress and are relieved by a bowel movement.
Treatment of IBS?
Reassurance. Maybe TCAs, fiber supplements, antidiarrheals. Tegaserod for constipation-predominant IBS.
Common causes of malabsorption?
Celiac disease (sprue), Whipple’s disease, short bowel syndrome, lactose intolerance, infection, pancreatic insufficiency.
What is tropical sprue?
Infectious ! Carribean farmer. Doesn’t improve with gluten avoidance. Treat w/ abx.
How is d-xylose helpful in malabsorption testing?
If it is absorbed, you know the problem is in the enzymes that should normally be breaking things down. Likely pancreatic etiology. If not, then the issue is the intestinal luminal border. (EGD + bx).
What is celiac sprue?
Gluten allergy. Auto-immune, IgA mediated.
Presentation of celiac sprue?
Diarrhea, bloating, +/- weight loss, +/- dermatitis herpetiformis.
TX of whipples?
trimethoprim sulfa or doxycycline.
What is a small bowel obstruction?
Defined as blocked passage of bowel contents through the small bowel. Fluid and gas can build up proximal to the obstruction → fluid and electrolyte im- balances and significant abdominal discomfort. The obstruction can be com- plete or partial, and strangulation of the bowel may occur.
What is absorbed in the prox duodenum?
folate, iron, calcium.
What should you worry about in malabsorption affecting duodenum?
Anemia, hypocalcemia (osteoporosis).
What is absorbed int he terminal ileum?
bile salts w/ fat soluble vitamins (ADEK).
What problems are associated w failure to absorb fat-soluble vitamins?
A - night blindness
D - osteoporosis
E - nystagmus
K - bleeding
Treatment of celiac sprue?
No gluten. Takes 3-4 months of work.
What makes SBO an emergency?
Later in the disease, peristalsis may disappear. Fever, hypotension, re- bound tenderness, and tachycardia suggest a surgical emergency. Also lactic acidosis.
What is whipple’s disease?
Infection w/ T. Whippeli.
Radiographic findings w/ SBO?
Abdominal films often demonstrate a stepladder pattern of dilated small-
bowel loops, air-fluid levels, and a paucity of gas in the colon. The presence of radiopaque material at the cecum is suggestive of gallstone ileus.
Dx of whipples?
EGD + bx. PAS+ microscopy. Organisms on electron microscope.
Surgical TX of SBO?
Surgery is required in cases of complete SBO, vascular compromise (necrotic bowel), or symptoms lasting > 3 days without resolution. Strangulated SBO associated with 25% mortality rate.
What is a small bowel obstruction?
Defined as blocked passage of bowel contents through the small bowel. Fluid and gas can build up proximal to the obstruction → fluid and electrolyte im- balances and significant abdominal discomfort. The obstruction can be com- plete or partial, and strangulation of the bowel may occur.
What causes SBO?
SBO may arise from adhesions from a prior abdominal surgery (60% of cases) or from hernias (10–20%), neoplasms (10–20%), intussusception, gallstone ileus, stricture due to IBD, volvulus, or cystic fibrosis (CF).
Risk factors for ileus?
Recent surgery/GI procedures, severe medical illness, immobility, hypokalemia or other electrolyte imbalances, hypothyroidism, DM, and medications that slow GI motility (e.g., anticholinergics, opioids).
Emesis w/ SBO?
early emesis is bilious and nonfeculent if the obstruction is proximal but feculent if it is distal.
Physical exam findings of ileus?
- Examination may reveal diffuse tenderness and abdominal distention, no peritoneal signs, and ↓ or absent bowel sounds.
- A rectal examination is required to rule out fecal impaction in elderly patients.
Physical exam findings w/ SBO?
- Abdominal exam often reveals distention, tenderness, prior surgical scars,
or hernias. - Bowel sounds are characterized by high-pitched tinkles and peristaltic
rushes.
Treatment of ileus?
stop narcs or antichols, fix hypokalemia as needed, decr or d/c oral feeds, NG suction
Lab findings w/ SBO?
- CBC may demonstrate leukocytosis if there is strangulation of bowel.
- Chemistries often reflect dehydration and metabolic alkalosis due to vomiting.
- Lactic acidosis is particularly worrisome, as it suggests necrotic bowel and the need for emergent surgical intervention.
Radiographic findings w/ SBO?
Abdominal films often demonstrate a stepladder pattern of dilated small-
bowel loops, air-fluid levels, and a paucity of gas in the colon. The presence of radiopaque material at the cecum is suggestive of gallstone ileus.
Treatment of SBO? Partial:
Supportive care may be sufficient and should include NPO status, NG suction, IV hydration, correction of electrolyte abnormal- ities, and Foley catheterization to monitor fluid status.
Surgical TX of SBO?
Surgery is required in cases of complete SBO, vascular compromise (necrotic bowel), or symptoms lasting > 3 days without resolution. Strangulated SBO associated with 25% mortality rate.
F/u after surgical tx of SBO?
A second-look laparotomy or laparoscopy may be performed 18–36 hours after initial surgical treatment to reevaluate bowel viability.
What is ileus?
Loss of peristalsis without structural obstruction.
Risk factors for ileus?
Recent surgery/GI procedures, severe medical illness, immobility, hypokalemia or other electrolyte imbalances, hypothyroidism, DM, and medications that slow GI motility (e.g., anticholinergics, opioids).
Presentation of ileus?
Presenting symptoms include diffuse, constant, moderate abdominal dis- comfort; nausea and vomiting (especially with eating); and an absence of flatulence or bowel movements.
Physical exam findings of ileus?
- Examination may reveal diffuse tenderness and abdominal distention, no peritoneal signs, and ↓ or absent bowel sounds.
- A rectal examination is required to rule out fecal impaction in elderly pa- tients.
Imaging to dx ileus?
Diffusely distended loops of small and large bowel on supine AXR with air-fluid levels on upright view.
Treatment of ileus?
stop narcs or antichols, fix hypokalemia as needed, decr or d/c oral feeds, NG suction
