Physical causes of GIT disorder

Coarse Food

The mucous membrane of the stomach can be irritated mechanically and even physically, damaged by a large amount of food taken per meal as well as by the use of uncomminuted, rich in crude vegetable fiber (like radish, turnip, kidney bean, unpeeled peas, unripe fruit, grapes, raisins, gooseberry, currant, dates, whole wheat bread and etc.) and connective tissue (cartilages, sinewy meat, fowl and fish skin and etc.) products.

Also, coarse plant food that provides a lot of undigested residues (fruit, vegetables, especially their peel, whole-grain bread), fatty and heavy food activates intestinal peristalsis which results in diarrhea. Such food may also cause enteritis - an inflammation of the small intestine.

Hot or Cold

The temperature of the food we eat plays its own vital part in the development of the chronic diseases of the digestive system. Both too cold (below 7°C) and excessively hot (above 70°C) food and drinks cause digestive disorders. Thus, increased excretory function and acidity of the gastric contents with the following weakening and decline in the digestive power of the gastric juice are caused by cold food. It also provokes increased motor function of the stomach and intestine, and; thus, food leaves stomach and small intestine prematurely which leads to intestine diseases. The use of  excessively hot food provokes gastric mucosa atrophy which is accompanied by a sharp decrease in secretion of hydrochloric acid and pepsin in gastric juice. The habit of drinking hot tea or eating hot soup may lead to chronic gastritis and esophagus disorders.
So the temperature of food should be not be too low or too high so not to damage the mucosa of the gastrointestinal tract. The optimal temperature of the cold dishes is between 10°C and 15°C, and for the hot dishes - 60°C and 65°C.

Foreign bodies

These are various objects that have gotten into the gastrointestinal tract from outside or have been formed in it (gallstones, gastrolith) and due to their structure cannot be used as food in normal conditions. Although, in most of the cases, foreign bodies pass through the gastrointestinal tract without complications, sometimes there are specific exceptions.

Thus, those that are large or have sharp edges and spikes may stay in the body. Small battery (for example, from electronic watch) causes coagulation necrosis of the esophagus mucosa (hydrochloric acid in stomach neutralizes such risk). Sharp objects (long needle, pin) occasionally penetrate in the mucosa which can be accompanied by perforation of the stomach wall with the development of peritonitis. Actually, sharp objects may cause perforation of any part of the gastrointestinal tract. The objects longer than 2.35 inches often get stuck in the duodenum, whereas, solid objects may get stuck in any part of the digestive tract. Heavy metal objects (like small shot) sometimes encapsulate in the stomach wall. Large foreign bodies that stay in the stomach for a long time may cause pressure ulcer of the wall with bleeding and perforation.

Radiation

Human digestive tract is lined with epithelium - stratified squamous and simple columnar. This epithelium, particularly in the intestine and, especially, in the small intestine, regenerates pretty actively – about once every three days. Therefore, the cells of the epithelium are constantly dividing, and these cells are particularly sensitive to radiation. After the death of young and dividing cells epithelium cannot regenerate, and, thus, depending on the radiation dose, enteropathy (intestine disorder) may lead to the absorption worsening, and in worst cases, even to bleedings, ulcers and perforation of the intestine walls with necrosis.

All the patients who have undergone chemotherapy have intestinal disorders. Radiation therapy may induce inflammation and swelling of the esophagus, stomach and intestine causing pain, diarrhea, vomiting or nausea.