Acknowledgment The author gratefully acknowledges the important and valuable contributionsof the authors of previous editions, Drs. Ciaran P. Kelly, Jerry S.Trier, and Richard J. Farrell. Definitions Celiac disease is a chronic, immune-mediated enteropathy that is precipitated by dietary gluten in…
Short bowel syndrome (SBS) is characterized by malabsorption due to congenital absence or resection of large portions of the small intestine, typically leaving the adult with 150 to 200 cm of functional small bowel. Individuals with SBS have lost their…
In its most simplistic form, the term SIBO describes a condition of excess bacteria in the small intestine. Although the phrase SIBO remains clinically relevant, it oversimplifies the rapidly evolving complexity of this disorder that has both intestinal and extra-intestinal…
In the past, it was believed that most malabsorptive diseases manifested with diarrhea, steatorrhea, or both. It is now recognized that many malabsorptive disorders, such as celiac disease, might have subtle clinical presentations or mainly extraintestinal manifestations (e.g., anemia, bone…
The U.S. Department of Health and Human Services and the U.S. Department of Agriculture publish dietary guidelines for Americans every 5 years based on the most current evidence in nutrition science. These recommendations aim to promote health, prevent chronic disease…
Acknowledgments This work was supported by National Institutes of Health grant CA190710 and Welch Endowed Chair in Biochemistry, Grant No. BI-0028, at Texas Tech University Health Sciences Center. Digestion and absorption of dietary nutrients constitute the primary physiologic function of…
The GI tract processes 8 to 9 L of fluid daily that is derived from oral intake and endogenous exocrine secretions. Intestinal fluid absorption functions with 98% efficiency, allowing only 100 to 200 mL to be excreted each day. The…
Each day, 1200 to 1500 mL of ileal effluent enter the colon, 200 to 400 mL of which are excreted as stool. The colon mixes its contents to facilitate transmural exchange of water, electrolytes, and short-chain fatty acids and, in…
Efficient absorption of nutrients and maintenance of orderly aboral movement of chyme and indigestible residues are the most important goals of small intestinal motor and sensory function. Small intestinal motility is also critically important in preventing SIBO (see Chapter 105…
Anatomy Macroscopic Features Small Intestine The small intestine is a specialized tubular structure within the abdominal cavity in continuity with the stomach proximally and the colon distally. The small bowel increases in length from about 250 cm in the term…