Diarrhea is defined as the presence of liquid stools, rather than the typical formed, or harder stools that are thought of as normal. But, rather than merely being liquidity, the definition also allows for frequency, in that more than 3 stools over a 24 hour period is generally considered to be abnormal, at least in the industrialized societies. The weight of the average daily stool, or the total weight of all stools over a 24 hour period is said to be about 200 grams, and with diarrhea, for more reasons than one or two, the weight of the stools is usually greater. In this article, we will discuss some of the reasons for diarrhea, the current treatments that can be used safely, as well as some theory. However, and as in all cases in medicine, this information is to be used only for that – information. One should never rely on anything from the Internet or any other source unless it is first reviewed by a trained professional, preferably one with whom you have a sense of respect. Never treat anyone, particularly children, through information contained on the Internet, a book, etc. Rather, it is far better and more appropriate to check with your health care professional, i.e., a physician, physician assistant, or a nurse practitioner about what you read and how it may apply to your specific situation. This applies to all printed matter, not just this article and it really doesn't matter who wrote it. Period. Now, let's get to the topic.
Diarrhea results when there is a disruption in the normal flow of nutrients in the gut, particularly water. Let's first examine the ways in which foods and water are absorbed in the gut and then it will be easier to explain why and how diarrhea can become a problem. During periods when very little is eaten or consumed, there is very little fluid in the intestines; but when three or more meals are eaten a day, the intestines contain about 9 liters of fluid, most of which are delivered to duodenum, or the tube that runs from the stomach to the small intestines. Only about 2 of those liters are the result of what is eaten; the remaining portion is made of intestinal fluids, or secretions, which aid in the digestion of the foods we eat.
What passes from one part of the intestine to the other really depends on what is eaten. For example, if someone should consume a lot of food containing sugar, which is largely hypertonic, there is a greater amount that passes through the jejunum, rather than that which enters the proximal part of the duodenum, which, again, is near the stomach. Hence, in that respect, hypertonic foods or liquids travel a longer distance. On the other hand, if a meal containing a great deal of steak, potatoes, and tea, for example, that are generally isotonic or hypotonic is consumed, the amount of material that transverses the duodenum is far greater, and, hence, it has a much shorter distance to travel before it gets digested. In either case, the point here is that the types of foods that are consumed are generally absorbed in different parts of the gut, and, hence the osmolality of the chyme (food stuff that is prepared for absorption) is changed. By the time the chyme reaches the ileum, which is considered to be the end of the small intestinal tract before emptying into the colon, most of the sugars, amino acids, and fats are already absorbed. The remaining solution is generally an isotonic salt solution that is then passed into the colon. What happens in diarrhea, then, and to make a rather long story extremely short (there is a lot more going on here that is not discussed), is a problem in the ability of each of the segments to absorb what is generally absorbed in that area. One or more segments can be involved. The result is, however, a depletion in the nutrients, especially the electrolytes, and, of course, dehydration, if not corrected.
