Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in the United States. While the American Association for the Study of Liver Diseases guidelines define NAFLD as hepatic steatosis detected either on histology or imaging without a secondary cause of abnormal hepatic fat accumulation, no imaging modality is recommended as standard of care for screening or diagnosis. Bedside ultrasound has been evaluated as a non-invasive method of diagnosing NAFLD with the presence of characteristic sonographic findings. Prior studies suggest characteristic sonographic findings for NAFLD include bright hepatic echoes, increased hepatorenal echogenicity, vascular blurring of portal or hepatic vein and subcutaneous tissue thickness. These sonographic characteristics have not been shown to aid bedside clinicians easily identify potential cases of NAFLD. While sonographic findings such as attenuation of image, diffuse echogenicity, uniform heterogeneous liver, thick subcutaneous depth, and enlarged liver filling of the entire field could be identified by clinicians from bedside ultrasound. The accessibility, ease of use, and low-side effect profile of ultrasound make bedside ultrasound an appealing imaging modality in the detection of hepatic steatosis. When used with appropriate clinical risk factors and steatosis involves greater than 33% of the liver, ultrasound can reliably diagnose NAFLD. Despite the ability of ultrasound in detecting moderate hepatic steatosis, it cannot replace liver biopsy in staging the degree of fibrosis. The purpose of this review is to examine the diagnostic accuracy, utility, and limitations of ultrasound in the diagnosis of NAFLD and its potential use by clinicians in routine practices.

Chronic constipation is a common, persistent condition affecting many patients worldwide, presenting significant economic burden and resulting in substantial healthcare utilization. In addition to infrequent bowel movements, the definition of constipation includes excessive straining, a sense of incomplete evacuation, failed or lengthy attempts to defecate, use of digital manoeuvres for evacuation of stool, abdominal bloating, and hard consistency of stools. After excluding secondary causes of constipation, chronic idiopathic or primary constipation can be classified as functional defecation disorder, slow-transit constipation (STC), and constipation-predominant irritable bowel syndrome (IBS-C). These classifications are not mutually exclusive and significant overlap exists. Initial therapeutic approach to primary constipation, regardless of aetiology, consists of diet and lifestyle changes such as encouraging adequate fluid and fibre intake, regular exercise, and dietary modification. Laxatives are the mainstay of pharmacologic treatment for potential long-term therapy in patients who do not respond to lifestyle or dietary modification. After a failed empiric trial of laxatives, diagnostic testing is necessary to understand underlying anorectal and/or colonic pathophysiology. No single test provides a comprehensive assessment for primary constipation; therefore, multiple tests are used to provide complementary information to one another. Dyssynergic defecation, a functional defecation disorder, is an acquired behavioural disorder of defecation present in two-thirds of adult patients, where an inability to coordinate the abdominal, recto-anal, and pelvic floor muscles during attempted defecation exists. Biofeedback therapy is the mainstay treatment for dyssynergic defecation aimed at improving coordination of abdominal and anorectal muscles. A large percentage of patients with dyssynergic defecation also exhibit rectal hyposensitivity and may benefit from the addition of sensory retraining. Our understanding of the pathophysiology of STC is evolving. The advent of high-resolution colonic manometry allows for the improved identification of colonic motor patterns and may provide further insight into pathophysiological mechanisms. In a minority of cases of STC, identification of colonic neuropathy suggests a medically refractory condition, warranting consideration of colectomy. The pathophysiology of IBS-C is poorly understood with multiple etiological factors implicated. Pharmacological advances in the treatment of primary constipation have added therapeutic options to the armamentarium of this disorder. Drug development in the secretagogue, serotonergic prokinetic, and ileal bile acid transporter inhibition pathways has yielded current and future medical treatment options for primary chronic constipation.

Patients with FI have significant neuropathy that affects the cortico-anorectal and spino-anorectal efferent pathways. The primary loci are the lumbo-rectal, lumbo-anal, sacro-rectal, and sacro-anal nerves; the cortico-spinal segment appears intact. Peripheral spino-anal and spino-rectal neuropathy might therefore contribute to the pathogenesis of FI.

Background: Linaclotide, a guanylate cyclase C agonist relieves irritable bowel syndrome with predominant constipation (IBS-C) symptoms, but how it improves pain in humans is unknown. Aims:To investigate the effects of linaclotide and placebo on the afferent and efferent gut-brain-gut signalling in IBS-C patients, in a randomised clinical trial. Methods:Patients with IBS-C (Rome III) and rectal hypersensitivity were randomised (2:1) to receive linaclotide (290 µg) or placebo for 10 weeks and undergo bi-directional gut and brain axis assessment using anorectal electrical stimulations and transcranial/transspinal-anorectal magnetic stimulations. Rectal sensations were examined by balloon distention. Assessments included abdominal pain, bowel symptoms and quality of life (QOL) scores. Primary outcomes were latencies of recto-cortical and cortico-rectal evoked potentials.Results: Thirty-nine patients participated; 26 received linaclotide and 13 received placebo. Rectal cortical evoked potentials latencies (milliseconds) were significantly prolonged with linaclotide compared to baseline (P1:Δ 19 ± 6, P < 0.005; N1:Δ 20 ± 7, P < 0.02) but not with placebo (P1:Δ 3 ± 5; N1:Δ 4.7 ± 5,P = 0.3) or between groups.The efferent cortico-anorectal and spino-anorectal latencies were unchanged. The maximum tolerable rectal volume (cc) increased significantly with linaclotide compared to baseline (P < 0.001) and placebo (Δ 29 ± 10 vs 4 ± 20, (P < 0.03). Abdominal pain decreased (P < 0.001) with linaclotide but not between groups. Complete spontaneous bowel movement frequency increased (P < 0.001), and IBS-QOL scores improved (P = 0.01) with linaclotide compared to baseline and placebo. There was no difference in overall responders between linaclotide and placebo (54% vs 23%, P = 0.13). Conclusions:Linaclotide prolongs afferent gut-brain signalling from baseline but both afferent and efferent signalling were unaffected compared to placebo. Linaclotide significantly improves rectal hypersensitivity, IBS-C symptoms and QOL compared to placebo.These mechanisms may explain the effects of linaclotide on pain relief in IBS-C patients. ClinicalTrials.Gov: Registered at Clinical trials.gov no NCT02078323.This is an open access article under the terms of the Creat ive Commo ns Attri bution-NonCo mmerc ial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations.

SummaryBackground and Aims-An epidemiological link between an increased body mass index and complaints of typical heartburn symptoms has been identified. It appears that increasing waist circumference, rather than overall weight is most important. Studies to date have not included minority, impoverished communities. Our aim was to determine the impact of obesity on the prevalence of reflux disease in an impoverished community while controlling for known confounders.