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GIq3 - cs.step
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01-27-2009, 05:10 AM
The best test for bacterial overgrowth
syndrome is: A) Quantitative stool culture. B) Stool leukocytes. C) 72-hour fecal fat. D) D-xylose breath test. E) B and D
01-27-2009, 05:10 AM
The patient™s D-xylose test is negative and you consider
the possibility of gluten-sensitive enteropathy. Of the following, the BEST test for the diagnosis of gluten-sensitive enteropathy is: A) Anti-endomysial antibodies. B) Tissue transglutaminase antibodies. C) Anti-gliadin antibodies. D) Radiolabeled wheat flour absorption test. E) None of the above.
01-27-2009, 05:11 AM
The results of his tissue transglutaminase test are positive.
You send him to a gastroenterologist, who educates him on gluten-sensitive enteropathy (aka celiac disease) and performs an endoscopy. A small bowel biopsy demonstrated blunted villi with a significant increase in intraepithelial lymphocytes, consistent with gluten-sensitive enteropathy. With a gluten-free diet, the patient experiences a significant increase in his energy level. Two years later he comes for a routine visit. He has gradually reintroduced some wheat products into his diet and tolerates this very well. What do you recommend? A) Resume gluten-free diet. B) Continue dietary challenge and repeat examination in 6 months. C) Repeat small bowel biopsy. D) Check tissue transglutaminase antibody titer. E) Avoid wheat, but try barley or rye products
01-27-2009, 05:11 AM
A 27-year-old female presents to your clinic complaining
of abdominal pain since yesterday. She rates it as 5 on a scale of 1“10 and reports that it is mostly dull and crampy. She thinks it is worse in the left lower quadrant. She denies any significant past medical history or family history. She has had no surgeries and is taking no medications. Her last menstrual period was 25 days ago and she has regular periods every 28 days. She is married and denies smoking or drinking. Her review of systems is positive for straining with bowel movements, but she denies bloody stools, fever, nausea, vomiting, or recent travel. She also denies urinary or vaginal symptoms. On physical examination, her vital signs are normal and her BMI is 41 kg/m2 (or 1 Iowa Unit, as we say in the Midwest). Her cardiopulmonary exam is normal, and she has good bowel sounds. She has vague tenderness in the left lower quadrant but no rebound tenderness or guarding. Also, you note firmness there. Her femoral pulses palpate equally well. Her pelvic exam reveals no discharge or tenderness, and her rectal exam reveals hard stool that is guaiac-negative. Urine studies are negative and she is not pregnant; a CBC is normal. What is the MOST appropriate step now? A) Abdominal CT. B) Serum electrolytes. C) Complete bowel rest. D) Reassurance and treatment of constipation
01-27-2009, 05:33 AM
A 22-year-old previously healthy male reports a 3-day
history of explosive and watery diarrhea. He is having up to 6 bowel movements per day. He recalls eating at a new Mexican restaurant 5 days ago. His head sinks a little low as he recalls drinking a œfish bowl sized margarita . . . or at least he thinks he remembers drinking it! He denies fever, blood in his stool, or recent travel. Multiple people ate the same food, but he is the only one who is sick. His vital signs are normal (including supine and standing blood pressures), and the remainder of the physical exam is remarkable only for mild, diffuse abdominal tenderness. What is the most likely diagnosis? A) Celiac sprue. B) Gastroenteritis. C) Lactose intolerance. D) Small bowel bacterial overgrowth. E) Clostridium difficile colitis.
01-27-2009, 05:39 AM
What is the MOST appropriate diagnostic or
therapeutic step to perform at this point? A) Order a CBC. B) Order electrolytes. C) Order stool examination for ova and parasites. D) Recommend hydration and antidiarrheals as needed. E) Order an abdominal film.
01-27-2009, 05:40 AM
In the treatment of which of the following
organisms are antibiotics CONTRAINDICATED? A) Campylobacter. B) Shigella. C) Clostridium difficile. D) E. coli subtype O157:H7 (enterohemorrhagic E. coli).
01-27-2009, 07:04 AM
hi jamesvu.. good to see u online...
1 The correct answer is D. The workup of bacterial overgrowth syndrome includes upper GI endoscopy and possible small bowel biopsy. GI hypomotility, small bowel dilatation, or small bowel diverticula support the diagnosis of bacterial overgrowth syndrome. The D-xylose breath test takes advantage of the fact that the bacteria responsible for bacterial overgrowth syndrome (gram-negative aerobes) catabolize D-xylose. The breath test measures radioactive CO2 that is formed as a result of bacterial breakdown of radioactive D-xylose. Of the others, stool leukocytes are pretty useless in general and do not have a good correlation with infectious causes of diarrhea (high falsepositive and false-negative rates). Fecal fat collection is useful in documenting fat malabsorption syndromes, including secondary to severe pancreatic insufficiency (e.g., cystic fibrosis with > 90% pancreatic dysfunction) and short bowel syndrome. HELPFUL TIP: Another option to diagnose bacterial overgrowth is empiric treatment for 7“10 days with medications to cover aerobes and anaerobes (cephalexin plus metronidazole, TMP/SMX plus metronidazole, amoxicillin/ clavulanate). Definitive treatment may require surgical intervention to shorten the bowel, resect diverticula, etc. 2 The correct answer is B. Tissue transglutaminase antibodies are sensitive and specific for gluten-sensitive enteropathy. Anti-endomysial IgA antibodies are also relatively sensitive and very specific for gluten-sensitive enteropathy. The definitive test (gold standard) is a small bowel biopsy. 3 The correct answer is A. While there is no good data on the benefit of a long-term gluten-free diet in patients who can tolerate small amounts of gluten, several factors argue for continuing a gluten-free diet. The first is that many patients will have subclinical nutrient deficiencies if they reintroduce gluten. The second is that there is some data to suggest that patients who reintroduce gluten may have increased mortality from GI malignancy despite the fact that they are tolerating the gluten well. This is especially true in pediatric patients, in whom deficiencies may lead to stunted growth. HELPFUL TIP: Patients with gluten-sensitive enteropathy must be compulsive about their diet. Rice, corn, and soybean-based flours are safe to consume. 4 The correct answer is D. While constipation can mean different things to different people, it is generally defined as fewer than 3 stools a week and is usually associated with straining while defecating, hard stools, or lack of urge. It is a clinical diagnosis, and laboratory or radiologic evaluation is not needed except when the diagnosis is not clear. The history and physical exam in this patient effectively rule out more concerning causes of abdominal pain, and further workup is not needed. HELPFUL TIP: Since the most common metabolic causes of constipation are diabetes, pregnancy, electrolyte abnormalities, and hypothyroidism, consider electrolytes, glucose, and thyroid tests in patients with the appropriate clinical picture. Patient education is a key part of the treatment of constipation. Once organic causes have been ruled out (usually history and exam are enough), the patient should be advised to increase fluid and fiber intake. Regular exercise may increase colonic activity and should be recommended for every patient. Bowel retraining is often important, and having patients try to empty their bowels at the same time every day can be helpful. If all the above are not sufficient, appropriate laxatives can be prescribed for judicious use. HELPFUL TIP: Increasing fiber intake to 20“30 grams per day is usually effective. Soluble fiber, available naturally (whole wheat products) or commercially (psyllium preparations like Metamucil), is more helpful than insoluble fiber. The limiting side effect of fiber is bloating, which can be overcome by increasing fiber slowly. MEDICATIONS FOR CONSTIPATION Stool Softeners and Lubricants Examples: docusate and mineral oil Not very effective for chronic constipation Bulk-forming Laxatives Examples: psyllium, methylcellulose, polycarborphil Increase stool volume and diameter by retaining fecal water Decrease transit time and reduce straining Osmotic Laxatives Sorbitol and lactulose are nonabsorbable sugars that are broken down by colonic bacteria to short-chain fatty acids that increase stool osmolarity Cationic laxatives include saline and magnesium products, which work by increasing intraluminal water content by osmotic effects Polyethylene glycol (Miralax) is well tolerated and effective Stimulant Laxatives Examples: anthraquinones (e.g., senna), phenylmethanes (e.g., bisacodyl), and castor oil Should be used as agents of last resort, as chronic use can lead to damage of the colonic neural circuit Helpful Hint : Senna is an anthraquinone, which is a stimulant laxative. These types of laxatives can cause melanosis coli and may result in changes to the gastrointestinal motility. Stimulant laxatives are useful in certain situations (e.g., with chronic narcotic administration, as a third- or fourth-line agent for chronic constipation, for occasional use in addition to other agents). The other laxatives and stool softeners are appropriate first-line agents 5 The correct answer is B. This is always a dilemma. It can be difficult to differentiate acute gastroenteritis from food poisoning. What makes gastroenteritis more likely is that there is no clustering of cases among people who ate the same food. The other thing that makes B correct is that the other answers are clearly wrong! HELPFUL TIP: Acute diarrhea is defined as increased frequency or decreased consistency of stool lasting < 3 weeks. In textbooks, diarrhea is often approached by pathophysiologic mechanism: secretory, inflammatory (exudative), osmotic, and disordered motility. However, in practice this approach is not as useful as considering causes 6 The correct answer is D. No workup is needed for a mild case of acute diarrhea, since such cases are usually self-limited. Generally, the history and physical exam should provide the diagnosis and indicate need for further workup. Further workup and treatment are indicated if the patient has severe or bloody diarrhea, dehydration, systemic toxicity, or severe pain. 7 The correct answer is D. The use of antibiotics in patients with shiga-toxin-producing E. coli (E. coli subtype O157:H7 and others, the enterohemorrhagic E. coli) may increase the risk of developing hemolytic uremic syndrome. The use of antibiotics is indicated in Campylobacter, Shigella, and Clostridium. For Clostridium difficile, metronidazole is the drug of choice. A fluoroquinolone can be used to treat the other two organisms HELPFUL TIP (YET AGAIN): The above recommendations are for immunocompetent adults. In those who are immunosuppressed (e.g., HIV), are frail, or have coexisting disease, more liberal criteria for treatment can be used. |
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