Gastrointestinal tract stomach

The largest use of endoscopic techniques is in the examination of the gastrointestinal tract. Upper intestinal endoscopy is the examination of the esophagus, stomach, and proximal duodenum. Colonoscopy is the examination of the colon, large intestine, and in some cases the distal parts of the small intestine. Cholangiopancreatography is the examination of the biUary tree and pancreas. 

Swallowing. If it is sufficiently irritant or caustic, a swallowed material may cause local effects on the mouth, pharynx, esophagus, and stomach. Additionally, carcinogenic materials may induce tumor formation in the alimentary tract. Also, the gastrointestinal tract is an important route by which toxic materials are absorbed. The sites of absorption and factors regulating absorption have been reviewed (42,43). 

Gastrointestinal tract-decrease in secretions of the stomach, decrease in gastric and intestinal movement (motility)... 

In severe cases, or those refractory to treatment, truncal and limb weakness may be accompanied by involvement of masticatory, bulbar, and respiratory muscles. However the most life-threatening clinical manifestations are those affecting the gastrointestinal tract, since stomach ulceration can occur and death from perforation and peritonitis are not unknown. Medication with steroidal antiinflammatory agents is necessary but weakens the childrens resistance to infection, so that systemic spread of usually self-limiting disorders, such as candidiasis, may occasionally occur. 

Milieu conditions in gastrointestinal tract can influence the pectin structure and properties. Under the acid conditions of the stomach (pH 2-4) extraction of pectin from plant cell walls and hydrolysis of side chains can occur. In small intestine (pH 5-6) -elimination of main chains or de-esterification seems to be possible. In caecum and colon (pH 6-8) a strong fermentation of pectin takes place causing depolymerization to oligomers and leading to formation of short chain fatty acids and gases. The presence of OligoGalA is not yet clarified. 

Irritable bowel syndrome (IBS) is a disorder of the gastrointestinal tract that interferes with the normal functions of the colon. At various points in the past, IBS has been referred to as mucous colitis, spastic colon, irritable colon, or nervous stomach. IBS is generally described as afunctional disorder rather than a disease per se. A functional disorder involves symptoms that cannot be attributed to a specific injury, infection, or other physical problem. A functional disorder occurs because of altered physiologic processes rather than structural or biochemical defects and may be subject to nervous system influence. IBS is associated with frequent fluctuation in symptoms, loss of productivity, and decreased quality of life. Although IBS has been referred to as functional bowel disease, true functional bowel disease may be more indicative of widespread gastrointestinal involvement including (but not limited to) the colon. 

Webb LM, Taylor DM, Williams DR. 1998. Computer modeling of the chemical speciation of lanthanide and actinide elements in the human gastrointestinal tract Mouth and stomach. Radiat Prot Dosim 79(l/4) 219-222. 

Therefore, for a nondegradable drug dosed in immediate release dosage forms, the absorption and transit in the gastrointestinal tract can be depicted as follows. Stomach ... 

KA Kelly. Motility of the stomach and gastroduodenal junction. In LR Johnson, ed. Physiology of the Gastrointestinal Tract. New York Raven Press, 1981, pp 393-410. 

---