Large intestine

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Large intestine

Postby M.Team » Fri Jul 22, 2016 7:45 pm

Crohn's disease:
A. Is caused by Mycobacterium paratuberculosis.
B. Is more common in Asians than in Jews.
C. Tends to occur in families.
D. Is less frequent in temperate climates than in tropical ones.
E. Is improved by smoking.
Answer: C

DISCUSSION: The cause of Crohn's disease is unknown. No specific microorganism has been identified as a pathogen, and no clear-cut environmental factor, such as smoking, has been implicated, even though many patients with Crohn's disease are heavy smokers. The disease does tend to occur in families. It is more common among Jews than Asians and among people who live in temperate climates than those in tropical ones.

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Re: Large intestine

Postby M.Team » Fri Jul 22, 2016 7:46 pm

Recurrence after operation for Crohn's disease:
A. Occurs after operations for ileal Crohn's but not colonic Crohn's.
B. Is usually found just proximal to an enteric anastomosis.
C. Rarely requires reoperation.
D. Occurs in 1% of patients at risk per year during the first 10 years after the operation.
E. Is prevented by maintenance therapy with corticosteroids.
Answer: B

DISCUSSION: Recurrence after operation for Crohn's disease often occurs just proximal to an enteric anastomosis or stoma and occurs at a rate of about 6% per year over the first 10 years after operation. Recurrence follows operations for both ileal and colonic Crohn's and is not prevented by medical therapy using corticosteroids. Reoperation is required for 30% to 50% of subjects at risk.

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Re: Large intestine

Postby M.Team » Fri Jul 22, 2016 7:46 pm

Excision rather than bypass is preferred for surgical treatment of small intestinal Crohn's because:
A. Excision is safer.
B. Bypass does not relieve symptoms.
C. Excision cures the patient of Crohn's disease but bypass does not.
D. Fewer early complications appear with excision.
E. The risk of small intestine cancer is reduced.
Answer: E

DISCUSSION: Bypass of segments of small bowel affected with Crohn's disease is a safe operation with few complications, and one that usually relieves symptoms promptly. It leaves diseased bowel behind, however, which can flare in the future and can develop carcinoma. Excision, though it does not cure the Crohn's disease, removes the areas of severe involvement and so eliminates the risk of developing cancers in these segments.

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Re: Large intestine

Postby M.Team » Fri Jul 22, 2016 7:47 pm

The most common indication for operation in Crohn's disease of the colon is:
A. Obstruction.
B. Chronic debility.
C. Bleeding.
D. Perforation.
E. Carcinoma.
Answer: B

DISCUSSION: Crohn's disease of the colon usually leads to operation because of chronic debility and inanition unresponsive to medical therapy. Obstruction, perforation, and bleeding are uncommon complications of colonic Crohn's. While for persons with Crohn's colitis the risk of carcinoma of the colon is four to six times that of a healthy control population, the presence of cancer in the colon is an unusual cause for operation for Crohn's colitis. In fact, most patients with Crohn's have their colons excised before sufficient time has elapsed for cancers to appear. Cancers usually do not appear until 10 years or more after the onset of disease.

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Re: Large intestine

Postby M.Team » Fri Jul 22, 2016 9:29 pm

The test with the highest diagnostic yield for detecting a colovesical fistula is:
A. Barium enema.
B. Colonoscopy.
C. Computed tomography (CT).
D. Cystography.
E. Cystoscopy.
Answer: E

DISCUSSION: Of the tests listed above, cystoscopy provides the highest diagnostic yield, between 80% and 95%. The most common finding on cystoscopy is localized inflammation and bullous edema of the bladder mucosa. Actual demonstration of the fistula is unusual, no matter which test is utilized. Barium enema usually demonstrates some abnormality; however, precise delineation of the fistula occurs in only 30% of cases. Recently, CT has been shown to be useful in diagnosing colovesical fistula with accuracy approaching that of cystoscopy. The low diagnostic yields (20%) of cystography and colonoscopy have limited their use.

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Re: Large intestine

Postby M.Team » Fri Jul 22, 2016 9:30 pm

Which of the following is not true of diverticular disease:
A. It is more common in the United States and Western Europe than in Asia and Africa.
B. A low-fiber diet may predispose to development of diverticulosis.
C. It involves sigmoid colon in more than 90% of patients.
D. Sixty per cent develop diverticulitis sometime during their lifetime.
E. It is the most common cause of massive lower gastrointestinal hemorrhage.
Answer: D

DISCUSSION: Among all patients with diverticular disease only 20% can be expected ever to develop symptoms related to their disease. The development of diverticular disease has been linked to low-fiber diets, a type of diet more common in industrialized countries such as the United States and Western Europe. This correlates with the increased prevalence of diverticular disease in these regions. Diverticular hemorrhage accounts for 50% to 60% of all cases of massive lower gastrointestinal hemorrhage.

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Re: Large intestine

Postby M.Team » Fri Jul 22, 2016 9:30 pm

The most common indication for surgery secondary to acute diverticulitis is:
A. Abscess.
B. Colonic obstruction.
C. Colovesical fistula.
D. Free perforation.
E. Hemorrhage.
Answer:A

DISCUSSION: Complications of diverticular disease include obstruction, fistulization, hemorrhage, and infection. By far, the most common indication for surgery is intra-abdominal abscess formation, accounting for 40% to 50% of all complications of diverticulitis. Intestinal obstruction accounts for another 10% to 30%, while free perforation can be expected in 10% to 15% of complicated cases of diverticulitis. Fistulization is the least common problem, occurring in only 4% to 10% of complicated cases. Bleeding from diverticula occurs in the complete absence of inflammation.

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Re: Large intestine

Postby M.Team » Fri Aug 05, 2016 9:15 pm

Which of the following statements about familial adenomatous polyposis (FAP) is/are true?
A. Inherited in an autosomal-dominant manner, this genetic defect is of variable penetrance, some patients having only a few polyps whereas others develop thousands.
B. The phenotypic expression of the disease depends mostly on the genotype.
C. Appropriate surgical therapy includes total abdominal colectomy with ileorectal anastomosis and ileoanal pull-through with rectal mucosectomy.
D. Panproctocolectomy with ileostomy is not appropriate therapy for this disease.
E. Pharmacologic management of this disease may be appropriate in some instances.
Answer: C

DISCUSSION: The genetic defect is of high penetrance: nearly all affected patients develop hundreds to thousands of polyps. By definition, at least 100 polyps must be present. Recent studies have shown that even patients with the identical point mutation can exhibit variability in the phenotypic expression, suggesting that environmental or other genetic factors play a significant role. The phenotypic variations concern age at onset, size of polyps, density of polyps, and extracolonic manifestations of the disease. Although panproctocolectomy with ileostomy is not well-accepted by patients because of the stoma, acceptable surgical options include panproctocolectomy with ileostomy, total colectomy with ileorectal anastomosis, and ileoanal anastomosis with rectal mucosectomy. No pharmacologic agents have been demonstrated to be efficacious in this condition, though several have been tried.

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Re: Large intestine

Postby M.Team » Fri Aug 05, 2016 9:15 pm

Surgical alternatives for the treatment of ulcerative colitis include all of the following except:
A. Colectomy with ileal pouch–anal anastomosis.
B. Left colectomy with colorectal anastomosis.
C. Proctocolectomy with Brooke ileostomy or continent ileostomy.
D. Subtotal colectomy with ileostomy and Hartmann closure of the rectum.
Answer: B

DISCUSSION: Ulcerative colitis is a mucosal inflammatory disease confined to the rectum and colon. It can thus be cured by total proctocolectomy. For that reason, the standard of therapy for many years was total proctocolectomy and ileostomy. In an effort to avoid permanent ileostomy a number of other alternatives have been evaluated, including subtotal colectomy with ileorectal anastomosis, proctocolectomy with continent ileostomy, and colectomy with endorectal ileal pouch–anal anastomosis. In the past, subtotal colectomy with ileorectal anastomosis was accepted as a compromise operation, with the knowledge that disease-bearing rectal tissue was retained. Because other definitive alternatives are currently available, ileorectal anastomosis is no longer appropriate for elective surgical treatment of ulcerative colitis. In an acutely ill patient or when the diagnosis is in question, subtotal colectomy with ileostomy and Hartmann closure of the rectum is the most expeditious choice and allows later restorative surgery. Partial colectomy has never been an acceptable alternative for elective operative management of ulcerative colitis; thus, left colectomy with colorectal anastomosis would not be an appropriate alternative.

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Re: Large intestine

Postby M.Team » Fri Aug 05, 2016 9:16 pm

Which finding(s) suggest(s) the diagnosis of chronic ulcerative colitis as opposed to Crohn's colitis?
A. Endoscopic evidence of backwash ileitis.
B. Granulomas on biopsy.
C. Anal fistula.
D. Rectal sparing.
E. Cobblestone appearance on barium enema.
Answer: A

DISCUSSION: It has become increasingly important to distinguish between ulcerative colitis and Crohn's colitis, since the operative therapy for the two disease processes is quite different. Patients with ulcerative colitis are candidates for colectomy with ileoanal anastomosis, whereas Crohn's disease is a clear contraindication to this operation. Clinical findings suggestive of Crohn's disease include anal fistula or other perianal disease, though it must be kept in mind that approximately 10% of patients with ulcerative colitis may also develop perianal problems secondary to their chronic diarrhea. Endoscopic or radiographic evidence of rectal sparing is powerful evidence against a diagnosis of ulcerative colitis. However, if patients have been treated with steroid or salicylate enemas, they may have less active disease in the rectum than in the more proximal colon, a finding that could mislead the clinician about the presence or degree of rectal involvement. The deep linear ulcers that lead to a cobblestone appearance on barium enema are strongly suggestive of Crohn's disease. Typically, ulcerative colitis is confined to the rectum and colon. Frank small bowel involvement is suggestive of Crohn's disease; however, patients with active pancolitis may have secondary inflammation of the ileum, which has been called backwash ileitis. This clears after colectomy. The differential diagnosis may ultimately rely on histologic evaluation. Endoscopic biopsies are not generally useful since they only sample 3-mm. deep segments of mucosa and submucosa. Transmural inflammation and granulomas on surgical pathologic specimens are pathognomonic of Crohn's disease.


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