Disorders Of The Anorectum And Pelvic Floor An Issue Of Gastroenterology Clinics

This issue provides important updates on the management of disorders of the anorectum and pelvic floor. Expert authors provide information on hemorrhoidal issues, anorectal anatomy and imaging techniques, fissure and anal stenosis, rectal prolapse, and anal abscess and fistula. Other articles are devoted to sexually transmitted and infectious diseases, treatment of radiation proctitis, and pruiritis ani. Readers will come away with a full understanding of the current strategies for diagnosis and management of these disorders.

Pelvic Floor Disorders, An Issue of Gastroenterology Clinics of North America, E-Book

Dr. Rao's issue provides a timely overview of the current diagnostic modalities for diagnosing disorders of the anorectum and pelvic floor. Detailed discussions are found on manometric, sensorimotor, and neurophysiological evaluations; radiological evaluations; and biofeedback therapy. Clinical presentation and management is discussed for functional fecal incontinence, urinary and fecal incontinence, hemorrhoids, and ileal pouch function, to name a few.

Three distinct types of contractions perform colonic motility functions. Rhythmic phasic contractions (RPCs) cause slow net distal propulsion with extensive mixing/turning over. Infrequently occurring giant migrating contractions (GMCs) produce mass movements. Tonic contractions aid RPCs in their motor function. The spatiotemporal patterns of these contractions differ markedly. The amplitude and distance of propagation of a GMC are several-fold larger than those of an RPC. The enteric neurons and smooth muscle cells are the core regulators of all three types of contractions. The regulation of contractions by these mechanisms is modifiable by extrinsic factors: CNS, autonomic neurons, hormones, inflammatory mediators, and stress mediators. Only the GMCs produce descending inhibition, which accommodates the large bolus being propelled without increasing muscle tone. The strong compression of the colon wall generates afferent signals that are below nociceptive threshold in healthy subjects. However, these signals become nociceptive; if the amplitudes of GMCs increase, afferent nerves become hypersensitive, or descending inhibition is impaired. The GMCs also provide the force for rapid propulsion of feces and descending inhibition to relax the internal anal sphincter during defecation. The dysregulation of GMCs is a major factor in colonic motility disorders: irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and diverticular disease (DD). Frequent mass movements by GMCs cause diarrhea in diarrhea predominant IBS, IBD, and DD, while a decrease in the frequency of GMCs causes constipation. The GMCs generate the afferent signals for intermittent short-lived episodes of abdominal cramping in these disorders. Epigenetic dysregulation due to adverse events in early life is one of the major factors in generating the symptoms of IBS in adulthood.

Dr. Kahi has assembled top experts to provide clinically focused articles on colonoscopy and polypectomy. The issue is divided into sections devote to Technique Fundamentals, Advances in Technique, Technology, Neoplasia Detection, Quality and Outcomes, and The Future. Everyone from early-career gastroenteorlogists to those late in their career should find this edition to be very valuable.

By the time this issue of Gastroenterology Clinics of North America is released, it will have been 16 years since infliximab was approved by the US Food and Drug Administration for the treatment of moderate to severe Crohn disease. Not only have we come a long way in understanding the efficacy and safety of infliximab, we are beginning to understand how and when to use the drug. Furthermore, as of this writing, we have five other biologic agents approved for either Crohn disease or ulcerative colitis, and there are many more molecules currently in drug development for these indications. In this issue,the Editors have assembled a collection of experts to provide the most cutting-edge information on the status of biologic therapy for inflammatory bowel disease.

With collaboration of Dr. Alan Buchman, Consulting Editor, Dr. Perry J. Pickhardt has created a comprehensive issue of Gastroenterology Clinics that looks at imaging techniques for gastrointestinal diseases. Experts in their respective fields have contributed clinical reviews in the following areas: Evaluation of Dysphagia: The Role of Barium Fluoroscopy; CT and MR Small Bowel Enterography: Current Status and Future Trends; Radiologic Assessment of Gastrointestinal Bleeding; CT Colonography: Implementation for Screening; Rectal MR for Cancer Staging and Surveillance; Defecography (fluoro vs MR); Noninvasive Imaging Techniques for Staging Liver Fibrosis; HCC Screening: Comparison of US, CT, and MR Approaches; Pancreatic Cystic Lesions; Overview of biliary imaging; Splenomegaly: Clinico-Radiologic Approach to the Differential Diagnosis; MR for Non-Traumatic Acute Abdominal Pain: Comparison with CT and US; and PET/MR: Current Clinical Status and Future Prospects. Gastroenterologists will come away with the knowledge they need to understand the latest imaging modalities for diagnosis and assessment of gastrointestinal diseases and disorders.