Olmesartan-associated enteropathy.

Olmesartan, an angiotensin-receptor blocker frequently prescribed for hypertension, has been commercially available since 2002. In 2012, olmesartan-associated enteropathy was described, and the Food and Drug Administration now requires a black-box warning for olmesartan regarding severe diarrhea. The disorder can be life-threatening and often requires hospitalization. We present three cases that represent different aspects of this disorder, as well as some unusual features.

Risk of colon perforation during colonoscopy at Baylor University Medical Center.

Colonoscopy is an important procedure in preventing colon cancer. The risk of colonic perforation during colonoscopy at the Baylor University Medical Center (BUMC) Gastrointestinal Laboratory was chosen as a surrogate marker for the safety of colonoscopy. A recent 2-year experience at BUMC was examined and compared with reports in the medical literature. The results are presented here along with a discussion of problems inherent with different health care systems and their ability to accurately track complications. It was concluded that colonoscopy at BUMC is as safe as that reported by comparable health care systems. The risk of perforation at BUMC was 0.57 per 1000 procedures or 1 in 1750 colonoscopies. Continued efforts to make colonoscopy safer are needed.

Impact of experience with a retrograde-viewing device on adenoma detection rates and withdrawal times during colonoscopy: the Third Eye Retroscope study group.

BACKGROUND: Colonoscopy has been adopted as the preferred method to screen for colorectal neoplasia in the United States. However, lesions can be missed because of numerous factors, including location on the proximal aspect of folds or flexures, where they may be difficult to detect with the forward-viewing colonoscope. The Third Eye Retroscope (TER) is a disposable device that is passed through the instrument channel of a standard colonoscope to provide a retrograde view that complements the forward view of the colonoscope during withdrawal. OBJECTIVE: To evaluate whether experience with the TER affects polyp detection rates and procedure times in experienced endoscopists who had not previously used the equipment. DESIGN, SETTING, PATIENTS: This was an open-label, prospective, multicenter study at 9 U.S. sites, involving 298 patients presenting for colonoscopy, evaluating the use of the TER in combination with a standard colonoscope. INTERVENTIONS: After cecal intubation, the TER was inserted through the instrument channel of the colonoscope. During withdrawal, the forward and retrograde video images were observed simultaneously on a wide-screen monitor. MAIN OUTCOME MEASUREMENTS: Primary outcome measures were the number and size of adenomas and all polyps detected with the standard colonoscope and with the colonoscope combined with the TER. Secondary outcome measures were withdrawal phase time and total procedure time. Each endoscopist examined 20 subjects, divided into quartiles according to the order of their procedures, and results were compared among quartiles. RESULTS: Overall, 182 polyps were detected with the colonoscope and 27 additional polyps with the TER, a 14.8% increase (P < .001). A total of 100 adenomas were detected with the colonoscope and 16 more with the TER, a 16.0% increase (P < .001). For procedures performed after each endoscopist had completed 15 procedures while using the TER, the mean additional detection rates with the TER were 17.0% for all polyps (P < .001) and 25.0% for adenomas (P < .001). For lesions 6 mm or larger, the overall additional detection rates with the TER for all polyps and for adenomas were 23.2% and 24.3%, respectively. For lesions 10 mm or larger, the overall additional detection rates with the TER for all polyps and for adenomas were 22.6% and 19.0%, respectively. The mean withdrawal times in the first and fourth quartiles were 10.6 and 9.2 minutes, respectively (P = .044). LIMITATIONS: There was no randomization or separate control group. The endoscopists judged whether each lesion could have been detected with the colonscope alone by using their standard technique. CONCLUSIONS: Polyp detection rates improved significantly with the TER, especially after 15 procedures, when the mean additional detection rate for adenomas was 25.0%. Additional detection rates with the TER for medium-size and large adenomas were greater than for smaller lesions. These results suggest that, compared with a colonoscope alone, a retrograde-viewing device can increase detection rates for clinically significant adenomas without detriment to procedure time or procedure complications. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT00969124.).

Stimulated active potassium secretion in a patient with colonic pseudo-obstruction: a new mechanism of secretory diarrhea.

BACKGROUND & AIMS: Secretory diarrhea is caused by inhibition of intestinal active sodium absorption and stimulation of active chloride secretion. The resulting increase in fecal sodium salts causes an isotonic increase in fecal water output. Abnormalities in potassium transport are not known to be a cause of secretory diarrhea. The aim of our report is to describe a patient with secretory diarrhea that was mediated by excess intestinal secretion of potassium. METHODS: A 78-year-old woman developed colonic pseudo-obstruction, complicated by severe diarrhea and hypokalemia. Her stools were collected quantitatively on 11 occasions and analyzed for electrolyte concentrations. Rectosigmoid potential difference was measured. RESULTS: The diarrheal fluid had a very high potassium concentration (130-170 mEq/L) and a very low sodium concentration (4-15 mEq/L). Stool potassium losses were as high as 256 mEq/day (normal, 9 mEq/day), and fecal sodium losses were never higher than 13 mEq/day. Potential difference between colonic lumen and a peripheral reference electrode was -14 mV (lumen side negative). CONCLUSIONS: Fecal potassium salts were the exclusive driving force for severe secretory diarrhea in a patient with colonic pseudo-obstruction. The high fecal output of potassium was due to stimulation of active colonic potassium secretion, possibly because of changes in autonomic nervous system activity and distention of the colon in association with colonic pseudo-obstruction. The extremely low fecal excretion of sodium indicates that active sodium absorption was not inhibited. This case study reveals an ion transport mechanism of secretory diarrhea that has not been previously appreciated.