tailieunhanh - Chapter 040. Diarrhea and Constipation

The annual economic burden to society may exceed $20 billion. Acute infectious diarrhea remains one of the most common causes of mortality in developing countries, particularly among children, accounting for 2–3 million deaths per year. Constipation, by contrast, is rarely associated with mortality and is exceedingly common in developed countries, leading to frequent self-medication and, in a third of those, to medical consultation. Population statistics on chronic diarrhea and constipation are more uncertain, perhaps due to variable definitions and reporting, but the frequency of these conditions is also high. . | Chapter 040. Diarrhea and Constipation The annual economic burden to society may exceed 20 billion. Acute infectious diarrhea remains one of the most common causes of mortality in developing countries particularly among children accounting for 2-3 million deaths per year. Constipation by contrast is rarely associated with mortality and is exceedingly common in developed countries leading to frequent self-medication and in a third of those to medical consultation. Population statistics on chronic diarrhea and constipation are more uncertain perhaps due to variable definitions and reporting but the frequency of these conditions is also high. United States population surveys put prevalence rates for chronic diarrhea at 2-7 and for chronic constipation at 12-19 with women being affected twice as often as men. Diarrhea and constipation are among the most common patient complaints faced by internists and primary care physicians and they account for nearly 50 of referrals to diarrhea and constipation may present as mere nuisance symptoms at one extreme they can be severe or life-threatening at the other. Even mild symptoms may signal a serious underlying gastrointestinal lesion such as colorectal cancer or systemic disorder such as thyroid disease. Given the heterogeneous causes and potential severity of these common complaints it is imperative for clinicians to appreciate the pathophysiology etiologic classification diagnostic strategies and principles of management of diarrhea and constipation so that rational and cost-effective care can be delivered. Normal Physiology While the primary function of the small intestine is the digestion and assimilation of nutrients from food the small intestine and colon together perform important functions that regulate the secretion and absorption of water and electrolytes the storage and subsequent transport of intraluminal contents aborally and the salvage of some nutrients after bacterial metabolism of .