Chemical causes of GIT disorders

Tobacco smoke

tobaccoNicotine, ammonia, acids, tars and other substances contained in the tobacco smoke have an irritant effect on the oral mucosa and salivary glands that are accompanied by increased salivation. Together with saliva some parts of the tobacco smoke products are ingested into the stomach where they have an irritant impact on the mucous membranes of the stomach and bowels. That, in  turn,  promotes considerable emission of the gastric acid and leads to increased gastric acidity.

Also, nicotine affects the hypothalamic part of the brain where the nerve centers regulating appetite and satiation are located. In this case, the gastrointestinal tract is innervated via fibers of the vegetative nervous system that provides secretory, motor and absorptive functions of the digestive apparatus. Due to the spasms of the gastric outlet, the central nervous system does not get any signals informing it about hunger and, therefore, appetite is suppressed. Such behavior may provoke gastritis, then gastric and duodenal ulcer.

Another way how tobacco smoke affects human digestive tract is via blood. Such influence results in abnormality in hydrochloric acid, pepsin and enzymes secretion as well as change in vermicular movement and narrowing of the stomach and bowels blood vessels which quite often leads to gastritis, colitis and ulcers of the stomach and bowels.

Due to the abnormality of the motor and secretory functions, normal movement of food in the intestine is also disturbed. This, together with changes in secretion of digestive juices, causes spasms in bowels, periodic diarrhea or constipation, pain in the epigastrium, morning sickness, heartburn and bloating.


toxinsToxic substances that enter digestive organs together with food - salts of heavy metals, pesticides, noxious plants, chemical substances, poisonous mushrooms and etc. – cause diarrhea, abdominal pains, fever, vomiting and in severe cases such food poisoning may cause death.


drugsDrugs are chemicals and basically are toxins for the human gastrointestinal tract. Lots of medicines affect digestion, and digestive organs, thus, antibiotics taken to treat bacterial infections kill not only harmful bacteria but also intestinal flora (The beneficial bacteria that help our digestive tract functioning and protect us against pathogenic bacteria, fungi and parasites), and that usually results in bloating or diarrhea.

A large group of gastrointestinal disorders and diseases is associated with the intake of the nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, aspirin, and naproxen. These are usually prescribed for the treatment of conditions such as arthritis, radiculitis, stroke prevention, pain relief, fever reduction, and inflammation. Long-term use of NSAIDs may cause vomiting, diarrhea, dyspepsia and severe damage to the gastric mucosa, mainly to its antrum and duodenum (ulcers, hemorrhages, erosions).

It won’t be an overstatement if we say that almost any drug may cause some adverse reactions that affect human digestive system, so it’s extremely important to follow doctor’s advice on the medication prescribed in order to avoid such reactions or minimize them.



Once alcohol gets into the human body the first organs to suffer are esophagus and stomach, and the stronger is the liquor the more sever is the damage. When the esophagus is affected, it leads to esophagitis– an inflammation of the esophagus, which is characterized by the feeling of burning and pains when liquid and solid food passes to the stomach.

The mucosa of the stomach has glands producing gastric juice that contains pepsin, an enzyme that breaks down proteins, and hydrochloric acid required for this process. The result of the irritant effect produced by alcohol, the stomach mucosa begins secreting gastric juice (with the increased content of hydrochloric acid and mucus) intensely. Thus, the mucosa of the stomach gets thicker, and inflammation appears – the so-called hyperacid gastritis. Patients suffering from this type of gastritis complain of a general weakness, irritation, heartburn, acid regurgitation, pain in the epigastric area, nausea and sometimes even vomiting.

In case of continuous alcohol abuse the glands of the stomach mucosa that have been working actively become depleted. The production of gastric juice and hydrochloric acid is gradually reduced, and stomach mucosa gets thinner which leads to a chronic gastritis with reduced production of pepsin and without any production of hydrochloric acid at all. Patients with such condition have complaints of pain in the stomach, lack of appetite, heartburn and belching.

Alcohol induced gastritis is often accompanied by intestine inflammations (enterocolitis) caused by the effect of the alcohol produced on the secretion of the intestinal glands and pancreas, patients suffer from diarrhea and constipation. Also, alcohol contributes to the development of gastric and duodenal ulcers, as well as increases the risk of having gastric cancer.

Food Additives

Food additivesThey are used to make food taste better and look more appetizing. Initially natural components produced of natural products (for example, vegetable seasonings) were used for this purpose. However, with the development of chemistry as a science food additives are manufactured artificially. And such synthetic additives as colorants, flavor enhancers, preservatives, stabilizers, antioxidants, neutralizers, and thickeners have appeared. As of today, most of the products in the stores contain synthetic food additives, and some of them may sometimes cause digestive disorders (like E 154, E 220–226, E 320-322, E 338-341, E 343, E 405, E 407, E 450-454, E 461-466, E 626-635).

Although the majority of people show no negative reactions when eating food containing this or that food additive, there are people who are hypersensitive to these chemical substances, and in such people they can cause various digestive disorders like colicky pains or diarrhea.  

As a matter of fact, E-additives are particularly harmful for the whole body. They may cause not only digestive problems, but also allergic reactions, cardiovascular abnormalities, and many of them are carcinogenic.