Results of a Community-based, Randomized Study Comparing a Clear Liquid Diet With a Low-residue Diet Using a Magnesium Citrate Preparation for Screening and Surveillance Colonoscopies.

BACKGROUND: Current bowel preparations for colonoscopy include a clear liquid diet (CLD) along with consumption of a laxative. This dietary restriction along with large volume bowel preparations are barriers to compliance and willingness among patients in scheduling screening examinations. The aim of our study was to compare the efficacy and tolerability of a low-volume split dose magnesium citrate bowel preparation in patients on a low-residue diet (LRD) with those on a CLD. METHODS: In this single center, single blinded, randomized controlled trial, patients scheduled for outpatient colonoscopies were assigned to either a CLD or a LRD 1 day before the examination. Both groups received a split dose magnesium citrate preparation. The quality of the preparation was rated using the Boston Bowel Preparation Scale (BBPS). Patient satisfaction and side effects were evaluated using a questionnaire. RESULTS: We were unable to detect a significant difference in the BBPS scores between the LRD and CLD groups (P=0.581). A significantly higher percentage of patients in the LRD group rated the diet as easy compared with the CLD group (P<0.001). Satisfaction scores were significantly higher in the LRD group, compared with the CLD group (P<0.001). The side effect profiles of both arms were similar. CONCLUSIONS: There was no significant difference between LRD and CLD in patients using a magnesium citrate bowel preparation for screening and surveillance colonoscopies. Patient satisfaction scores were higher with a LRD compared with a CLD. We believe the LRD should be the recommended diet in patients using a standard bowel preparation for screening and surveillance colonoscopy.

The Future of the Private Gastroenterology Practice.

The future private gastroenterology practice will be a large multidisciplinary practice including a clinic, AEC, pathology services, infusion services, anesthesia services, pharmacy services, and imaging centers. Delivery of gastrointestinal (GI) services will be a team-based clinic with AEC access and improved quality of care. Competing technologies will drive practices to promote the value of colonoscopy as the best screening test for colon cancer. Artificial intelligence (AI) may significantly alter our approach to clinic and endoscopic services. The creative and intellectual capital of practice leaders will continue to define the private GI practice of the future.

Vascular KCNQ potassium channels as novel targets for the control of mesenteric artery constriction by vasopressin, based on studies in single cells, pressurized arteries, and in vivo measurements of mesenteric vascular resistance.

Pressor effects of the vasoconstrictor hormone arginine vasopressin (AVP), observed when systemic AVP concentrations are less than 100 pM, are important for the physiological maintenance of blood pressure, and they are also the basis for therapeutic use of vasopressin to restore blood pressure in hypotensive patients. However, the mechanisms by which circulating AVP induces arterial constriction are unclear. We examined the novel hypothesis that KCNQ potassium channels mediate the physiological vasoconstrictor actions of AVP. Reverse transcriptase polymerase chain reaction revealed expression of KCNQ1, KCNQ4, and KCNQ5 in rat mesenteric artery smooth muscle cells (MASMCs). Whole-cell perforated patch recordings of voltage-sensitive K+ (Kv) currents in freshly isolated MASMCs revealed 1,3-dihydro-1-phenyl-3,3-bis(4-pyridinylmethyl)-2H-indol-2-one (linopirdine)- and 10,10-bis(4-pyridinylmethyl)-9(10H)-anthracenone (XE-991)-sensitive KCNQ currents that were electrophysiologically and pharmacologically distinct from other Kv currents. Suppression of KCNQ currents by AVP (100 pM) was associated with significant membrane depolarization, and it was abolished by the protein kinase C (PKC) inhibitor calphostin C (250 nM). The KCNQ channel blocker linopirdine (10 microM) inhibited KCNQ currents in MASMCs, and it induced constriction of isolated rat mesenteric arteries. The vasoconstrictor responses were not additive when combined with 30 pM AVP, and they were prevented by the L-type Ca2+ channel blocker verapamil. Ethyl-N-[2-amino-6-(4-fluorophenylmethylamino)pyridin-3-yl] carbamic acid (flupirtine) significantly enhanced KCNQ currents, and it reversed constrictor responses to 30 pM AVP. In vivo, i.v. administration of linopirdine induced a dose-dependent increase in mesenteric artery resistance and blood pressure, whereas flupirtine had the opposite effects. We conclude that physiological concentrations of AVP induce mesenteric artery constriction via PKC-dependent suppression of KCNQ currents and L-type Ca2+ channel activation in MASMCs.

Successful endoscopic management of gastrojejunal anastomotic strictures after Roux-en-Y gastric bypass.

BACKGROUND: Roux-en-Y gastric bypass is the most frequently performed bariatric surgery for morbid obesity. Gastrojejunal anastomotic strictures are a relatively frequent postoperative complication. OBJECTIVE: To evaluate the clinical outcomes and therapeutic response to through-the-scope balloon dilation performed to treat anastomotic strictures after Roux-en-Y gastric bypass surgery. DESIGN: Single-center, retrospective study. SETTING: Academic medical center. PATIENTS: Between 1997 and 2005, 801 patients with morbid obesity underwent Roux-en-Y gastric bypass surgery at our institution. MAIN OUTCOME MEASUREMENTS: The development of an anastomotic stricture after Roux-en-Y gastric bypass surgery. The response to through-the-scope balloon dilation after diagnosis. RESULTS: Forty-three of 801 patients (5.4%) developed an anastomotic stricture (26 of 294 open surgeries [8.8%]; 17 of 507 laparoscopic surgeries [3.4%]; P < .001). Strictures were dilated to 15.5 +/- 0.4 mm. There were no perforations or clinically significant bleeding after dilation; 93% of the strictures were successfully managed with 1 or 2 endoscopic sessions. Dilation to at least 15 mm did not affect weight loss at 1 year when compared with the group without a stricture (percentage excess weight loss: stricture group, 76%; no stricture group, 74%). LIMITATIONS: Single-center, retrospective study. CONCLUSIONS: Endoscopic balloon dilation is a safe and effective method for the management of gastrojejunostomy strictures after Roux-en-Y gastric bypass. Dilation to at least 15 mm is safe and decreases the need for further endoscopic dilation.