Constipated patients with functional defecatory disorder have secondary rectal hyposensitivity due to altered rectal biomechanics.

BACKGROUND AND AIM: Rectal hyposensitivity (RH) is common in constipation and often coexists with functional defecatory disorder (FDD). Rectal sensory thresholds are routinely evaluated with the anorectal manometry probe; however, the gold standard for the assessment of rectal sensitivity is with a barostat, use of which is limited by time constraints and availability. A novel rapid barostat bag (RBB) may facilitate measurements of rectal sensitivity. The aim is to evaluate the relationship between RH (measured by the RBB) and FDD (defined as any minor disorder of rectoanal coordination by the London classification) in constipated patients. METHODS: Consecutive constipated patients referred for anorectal function testing underwent anorectal manometry with the 3D-HDAM probe as well as rectal sensation testing with the RBB pump. RH was defined by volume to first sensation >30%, urge to defecate >80%, or discomfort >100% (normalized to rectal capacity). RESULTS: Fifty-three percent of constipated patients had RH. Patients with FDD had a significantly increased volume to first sensation (134.5 mL vs 102.0, P = 0.02), urge to defecate (187.0 mL vs 149.0, P = 0.04), and rectal capacity (253.5 mL vs 209.0, P = 0.04) compared to constipated patients without FDD. There was no difference in normalized sensory thresholds (percent of rectal capacity) nor the prevalence of hyposensitivity to each sensory threshold nor overall hyposensitivity. CONCLUSION: Patients with FDD, when measured with the RBB, have increased sensory thresholds on volumetric distension, but RH was not observed when sensory threshold volume were normalized to rectal capacity. This may reflect "secondary" RH due to altered rectal biomechanics.

Identification of Group B Streptococcus Capsule Type by Use of a Dual Phenotypic/Genotypic Assay.

The group B streptococcus (GBS) capsular polysaccharide (CPS) is an important virulence factor which is also used for GBS typing. There are 10 CPS types (Ia, Ib, and II to IX). GBS that do not phenotypically type are considered nontypeable. All genes required for CPS synthesis are found on the GBS cps operon, which contains a highly variable CPS-determining region (cpsG-cpsK). The objective of this study was development of an assay to detect sialic acid on the GBS cell surface, followed by a genotypic PCR CPS typing assay. Sialic acid is located at the terminal end of the side chain of all known GBS CPS types. Sialic acid can be bound to commercially available lectins such as slug Limax flavus lectin. Biotinylated L. flavus-streptavidin-peroxidase complex was used in an enzyme immunoassay and dot blot assay to detect sialic acid. This was followed by a PCR typing scheme that was developed to target the serotype-determining region of the cps locus for Ia, Ib, and II to IX. Sialic acid from the CPS types Ia, Ib, and II to IX was detectable on the GBS cell surfaces of all previously identified CPS-typed GBS strains assayed. This was followed by the real-time PCR typing assay which successfully identified CPS Ia, Ib, and II to IX types. The combination of phenotypic and genotypic assays provides an accurate tool for detection of CPS expression and assignment of CPS typing. These assays have the potential to be used for CPS typing in large-scale epidemiological studies.

Variation of Laparoscopic Roux-en-Y Gastric Bypass Techniques: a Survey of 518 Bariatric Surgeons.

INTRODUCTION: Surgical technique varies dramatically in the performance of laparoscopic Roux-en-Y gastric bypass (LRYGB) and these differences can potentially lead to variation in outcomes. The objective of this study was to characterize surgical techniques used during LRYGB. METHODS: An anonymous 44-question survey was distributed by email to all bariatric surgeons with membership in the ASMBS, SAGES, and ACS from April to June 2020. Questions were designed to evaluate surgeon demographics, experience, and variation of techniques. Only surgeons who performed LRYGB within the past year were included for analysis. RESULTS: A total of 534 (18.8%) surgeons responded and the majority (97.0%) reported performing LRYGB in the past year. Surgeons were predominantly from the USA (77.8%). For preoperative work-up, 20.1% performed upper gastrointestinal series while 60.8% performed esophagogastroduodenoscopy. Limb length evaluation revealed mean Roux and biliopancreatic limb lengths of 124.1 ± 29.4 cm and 67.4 ± 32.2 cm, respectively. The gastrojejunostomy was most commonly formed using a linear stapler with handsewn closure of the common enterotomy (53.1%) and the jejunojejunostomy using a linear stapled anastomotic technique with handsewn closure of the common enterotomy (60.6%). The majority of surgeons closed the jejunojejunostomy mesenteric defect (91.1%) and one of the antecolic or retrocolic mesenteric defects (65.1%). Intraoperative leak tests were performed in 95.9% of cases. Only 22.1% of surgeons routinely performed upper gastrointestinal swallow studies postoperatively. CONCLUSIONS: There are wide variations in pre- and intraoperative practice patterns for LRYGB. Further clinical trials designed to evaluate the impact of these practice pattern differences on patient outcomes are warranted.

Manometric parameters, when measured with the 3-dimensional high-definition anorectal manometry probe, poorly predict prolonged balloon expulsion time.

BACKGROUND: There are little data evaluating the performance of the 3-dimensional high-definition anorectal manometry (3D-HDAM) system in the diagnosis of dyssynergic defecation. Physical properties of the thicker, rigid, 3D-HDAM probe may have implications on the measurements of anorectal pressures. AIM: Our aim was to compare 3D-HDAM to balloon expulsion test and magnetic resonance (MR) defecography. METHODS: Consecutive constipated patients referred for anorectal function testing at the Calgary Gut Motility Centre (Calgary, Canada) between 2014 and 2019 were assessed. All patients underwent anorectal manometry with the 3D-HDAM probe, and a subset underwent BET or MR defecography. Anorectal manometric variables were compared between patients who had normal and abnormal BET. RESULTS: Over the study period, 81 patients underwent both 3D-HDAM and BET for symptoms of constipation. 52 patients expelled the balloon within 3 minutes. Patients with abnormal BET had significantly lower rectoanal pressure differential (RAPD) (-61 vs. -31 mmHg for normal BET, p = 0.03) and defecation index (0.29 vs. 0.56, p = 0.03). On logistic regression analysis, RAPD (OR: 0.99, 95% CI: 0.97-0.99, p = 0.03) remained a negative predictor of abnormal BET. On ROC analysis, RAPD had an AUC of 0.65. There was good agreement between dyssynergic patterns on 3D-HDAM and defecographic evidence of dyssynergia (sensitivity 80%, specificity 90%, PLR 9, NLR 0.22, accuracy 85%). CONCLUSIONS: Manometric parameters, when measured with the 3D-HDAM probe, poorly predict prolonged balloon expulsion time. RAPD remains the best predictor of prolonged balloon expulsion time. The 3D-HDAM probe may not be the ideal tool to diagnose functional defecatory disorders.

Isolated colonic neurofibroma in the setting of Lynch syndrome: A case report and review of literature.

BACKGROUND: Gastrointestinal neurofibromas are commonly found in patients diagnosed with neurofibromatosis type 1. However, isolated gastrointestinal neurofibromas are a rare entity and only fourteen cases of isolated colorectal neurofibromas have been documented in literature. Isolated gastrointestinal neurofibromas have not been associated with Lynch syndrome (LS). Patients with LS are at an increased risk of colorectal cancer, and are recommended to undergo screening colonoscopy. CASE SUMMARY: A 33-year-old healthy female with a family history of LS was found to have unresectable polyp in the ascending colon on screening colonoscopy suspicious for malignancy. The patient was asymptomatic and had no stigmata of neurofibromatosis. A staging workup for colorectal cancer revealed no evidence of metastatic disease. A discussion with the patient resulted in the decision to undergo a segmental resection with ongoing surveillance. The patient underwent a laparoscopic right hemicolectomy. Histopathology was consistent with a gastrointestinal neurofibroma. Post-operatively, the patient recovered well. She will not require further treatment with regards to her colonic neurofibroma, but will continue to follow-up for ongoing surveillance of her LS. CONCLUSION: We present the first case of an isolated colonic neurofibroma in a patient with LS. This case explores considerations for the management of isolated gastrointestinal neurofibromas given the lack of guidelines in literature.