Gastroenteritis is inflammation of the gastrointestinal tract, involving both the stomach and the small intestine and resulting in acute diarrhea. It can be transferred by contact with contaminated food and water. The inflammation is caused most often by an infection from certain viruses or less often by bacteria, their toxins, parasites, or an adverse reaction to something in the diet or medication. ANATOMY AND PHYSIOLOGY
The GIT is composed of two general parts, the main GIT start from the mouth to esophagus, to Stomach to Small intestine to Large intestine to Rectum. The esophagus, stomach, large and small intestine, aided by the liver, gallbladder and pancreas convert the nutritive components of food into energy and break down the non-nutritive components into waste to be excreted.
oContains the lips, cheeks, palate, tongue, teeth, salivary glands, masticators/facial muscles and bones. oAnteriorly bounded by the lips.
oImportant for the mechanical digestion of food
oThe saliva contains SALIVARY AMYLASE or PTYALIN that starts the INITIAL digestion of carbohydrates The Esophagus
oA hollow muscular tube
oLength - 25cm
oLocated in the mediastinum, anterior to the spine, posterior to the trachea and heart oThe upper third contains skeletal muscles, contains the upper esophageal or hypopharyngeal sphincter oThe lower third contains smooth muscles and the esophago-gastric/cardiac sphincter is found here Physiology
oFunctions to carry or propel foods from the oropharynx to the stomach
The Small intestine
oGrossly divided into the Duodenum (proximal), Jejunum (middle) and Ileum (distal). oLongest segment, about 2/3 of the total length
oThe intestinal glands secrete digestive enzymes that finalize the digestion of all foodstuffs.
The Large intestine
oApproximately 5 feet long
1. The Cecum – widest diameter, prone to rupture
2. The Appendix
3. The Ascending colon
4. The Transverse colon
5. The Descending colon
6. The Sigmoid colon – most mobile, prone to twisting
7. The Rectum
8. The Anus
Acute gastroenteritis is usually caused by bacteria and protozoan. In the Philippines, one of the most common causes of acute gastroenteritis is E. histolytica. The pathologic process starts with ingestion of fecally contaminated food and water. The organism affects the body through direct invasion and by endotoxin being released by the organism. Through these two processes the bowel mucosal lining is stimulated and destroyed the eventually lead to attempted defecation or tenesmus as the body tries to get rid of the foreign organism in the stomach.
The client with acute gastroenteritis may also report excessive gas formation that may leads to abdominal distention and passing of flatus due to digestive and absorptive malfunction in the system. Feeling of fullness and the increase motility of the gastrointestinal tract may progress to nausea and vomiting and increasing frequency of defecation. Abdominal pain and feeling of fullness maybe relieved only when the patient is able to pass a flatus.
As the destruction of the bowel continues the mucosal lining erodes due to toxin, direct invasion of the organism and the action of the hydrochloric acid of the stomach. As the protective coating of the stomach erodes the digestive capabilities of the acid helps in destroying the stomach lining. Pain or tenderness of the abdomen is then felt by the patient. When the burrows or ulceration reaches the blood vessels in the stomach bleeding will be induced. Dysentery may be characterized by melena or hematochezia depending on the site and quantity of bleeding that may ensue. Signs of bleeding may be observed also through hematemesis.
As the bowel is stimulated by the organism and its toxin, the intestinal tract secretes water and electrolytes in the intestinal lumen. The body secretes and...