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.

The mammalian gastrointestinal mucosa is a rapidly self-renewing tissue in the body, and its homeostasis is preserved through the strict regulation of epithelial cell proliferation, growth arrest, and apoptosis. The control of the growth of gastrointestinal mucosa is unique and, compared with most other tissue in the body, complex. Mucosal growth is regulated by the same hormones that alter metabolism in other tissues, but the gastrointestinal mucosa also responds to host events triggered by the ingestion and presence of food within the digestive tract. These gut hormones and peptides regulate the growth of the exocrine pancreas, gallbladder epithelium, and the mucosa of the oxyntic gland region of the stomach and the small and large intestines. Luminal factors, including nutrients or other dietary factors, secretions, and microbes that occur within the lumen and distribute over a proximal-to-distal gradient, are also crucial for maintenance of normal gut mucosal regeneration and could explain the villous-height-crypt-depth gradient and variety of adaptation, since these factors are diluted, absorbed, and destroyed as they pass down the digestive tract. Recently, intestinal stem cells, cellular polyamines, and noncoding RNAs are shown to play an important role in the regulation of gastrointestinal mucosal growth under physiological and various pathological conditions. In this book, we highlight key issues and factors that control gastrointestinal mucosal growth and homeostasis, with special emphasis on the mechanisms through which epithelial renewal and apoptosis are regulated at the cellular and molecular levels.

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Why is it important tochew your food? Can you guess how long it takes for food to travel through your body? Could you possibly have twenty feet of small intestines? Where does that bad-smelling gas come from? Your digestive system is out of sight and out of mind -- until things don't go right. Then you may wonder how these important organs work! You'll find the answers in Seymour Simon's smooth, well-organized, and fascinating introduction to the digestive system. He explains how it works twenty-four hours a day, turning pizza, sandwiches, milk, and other food into energy and nutrients and waste. Striking photographs on every spread show how major organs including the stomach and intestines move food through your body, and how, eventually, waste is eliminated. Guts takes the mystery out of something that happens to everyone, every day, while at the same time sharing a sense of wonder about the human body.

This text features coverage of basic intestinal physiology, as well as the management of complications and unusual problems. Additional chapters and fully updated material consider laparoscopic-assisted colostomy and methods of urinary diversion in stoma management.

The digestive system is made up of the tongue, the esophagus, the stomach, the intestines, and other parts. But what does the digestive system do? And how do its parts work together to keep your body healthy? Explore the digestive system in this engaging and informative book.

Allergies, asthma, obesity, acne: these are just a few of the conditions that may be caused—and someday cured—by the microscopic life inside us. The key is to understand how this groundbreaking science influences your health, mood, and more. In just the last few years, scientists have shown how the microscopic life within our bodies— particularly within our intestines—has an astonishing impact on our lives. Your health, mood, sleep patterns, eating preferences—even your likelihood of getting bitten by mosquitoes—can be traced in part to the tiny creatures that live on and inside of us. In Follow Your Gut, pioneering scientist Rob Knight pairs with award-winning science journalist Brendan Buhler to explain—with good humor and easy-to-grasp examples—why these new findings matter to everyone. They lead a detailed tour of the previously unseen world inside our bodies, calling out the diseases and conditions believed to be most directly impacted by them. With a practical eye toward deeper knowledge and better decisions, they also explore the known effects of antibiotics, probiotics, diet choice and even birth method on our children’s lifelong health. Ultimately, this pioneering book explains how to learn about your own microbiome and take steps toward understanding and improving your health, using the latest research as a guide.

AN INSTANT NEW YORK TIMES BESTSELLER AS SEEN ON NETFLIX’S HACK YOUR HEALTH: THE SECRETS OF YOUR GUT “Everything you ever wanted to know about the gut (and then some).” —SELF Discover the secrets of your digestive system—and how to hone a healthy gut—plus new research on the mind-gut connection. With quirky charm, science star and medical doctor Giulia Enders explains the gut’s magic, answering questions like: What’s really up with gluten and lactose intolerance? How does the gut affect obesity? What's the connection between our microbiome and mental health? Why does acid reflux happen? In this revised edition of her beloved bestseller, Enders includes a new section on the brain-gut connection, and dives into groundbreaking discoveries of psychobiotics—microbes with psychological effects that can influence mental health conditions like depression and even stress. For too long, the gut has been the body’s most ignored and least appreciated organ. But it does more than just dirty work; it’s at the core of who we are, and this beguiling book will make you finally listen to those butterflies in your stomach: they’re trying to tell you something important.