Dehydration caused by frequent loose stools is often observed in patients with certain diseases of the gastrointestinal (GI) tract. Given this, which of the following treatments would be most effective in treating this symptom?

Question

Dehydration caused by frequent loose stools is often observed in patients with certain diseases of the gastrointestinal (GI) tract.  Given this, which of the following treatments would be most effective in treating this symptom?

Quizplus · Accepted Answer

11ecba2d_1030_5426_a3bf_09a62f92580a_MD0008_00 The gastrointestinal (GI) tract is composed of the esophagus, stomach, small intestine, and large intestine. Food broken down in the mouth travels down the esophagus and enters the stomach, which produces chyme, a semifluid mixture of partially digested food. Chyme flows into the small intestine, where macromolecules are further broken down and absorbed, along with water, by intestinal epithelial cells. The large intestine absorbs any remaining water and electrolytes. In general, nutrients (ie, solutes) absorbed by intestinal epithelial cells are transported into surrounding interstitial fluid before diffusing into capillaries, increasing the osmotic pressure (solute concentration) in the interstitial fluid and, subsequently, in the blood plasma. Because water generally flows from low to high osmotic pressure via osmosis, increased osmotic pressure within interstitial fluid and blood plasma increases intestinal water absorption. In contrast, some epithelial cells secrete ions into the intestinal lumen, increasing osmotic pressure within the intestine to draw water in and lubricate luminal surfaces. In this scenario, dehydration is caused by frequent loose stools in affected individuals. Loose (watery) stools may be due to decreased water absorption or increased water secretion in the intestinal tract. Chloride (Cl⁻) secretion from intestinal epithelial cells would increase the osmotic pressure of intestinal contents, drawing more water into the intestine and increasing the water content of stool. Therefore, drugs inhibiting luminal secretion of Cl⁻ would likely decrease water secretion into the intestine and make the stools less watery. (Choices A and C) Parasympathetic signals generally enhance peristalsis and motility of intestinal contents through the GI tract. Drugs that enhance parasympathetic activity and, consequently, peristalsis would increase the flow of chyme through the GI tract, decreasing the time available for nutrient and water absorption by intestinal cells and increasing (not decreasing) the excretion of watery stools. (Choice B) A drug that decreases glucose absorption would decrease osmotic pressure of the interstitial fluid and capillary blood plasma surrounding the intestine. Decreased osmotic pressure caused by reduced glucose absorption would likely decrease intestinal water absorption and increase (not decrease) the excretion of water in stool. Educational objective: Most nutrient and water absorption occurs as food moves through the small intestine. The large intestine absorbs any remaining water and electrolytes prior to waste excretion.

Dehydration Caused by Frequent Loose Stools Is Often Observed in Patients