Diseases of the gastrointestinal tract

In the following you will find a list and brief description of the most important diseases of the gastrointestinal tract. For more information, you will find a reference to the main article for the respective disease at the end of each section.

Classification of diseases of the stomach

In the following you will find the most common gastrointestinal disorders divided into:

  1. Diseases of the stomach
  2. Diseases of the intestine

Diseases of the stomach

Inflammation of the gastric mucosa / gastritis

An inflammation of the stomach lining, medical gastritis, is a common disease. One of the most common causes of gastritis is a colonization of the stomach with the bacterium Helicobacter pylori. But substances that irritate the gastric mucosa can also trigger inflammation, such as painkillers ("NSAIDs"), alcohol or cigarette smoke. To treat gastritis, the stomach's acid production is usually inhibited so that the mucous membrane can recover better. Acid blockers, so-called proton pump inhibitors, are used for this.

You can find detailed information on our website Inflammation of the stomach lining.
If gastritis occurs over a long period of time, it is Chronic gastritis.

Gastric ulcer

For a stomach ulcer, medically Gastric ulcer, it is a tumor of the gastric mucosa that usually develops as a result of gastric mucosal inflammation / irritation. Accordingly, the risk factors of a gastric ulcer are similar to those of gastric mucosal inflammation: a Helicobacter colonization, massive consumption of painkillers / alcohol and cigarette smoke can promote the development of a gastric ulcer. A serious complication of gastric ulcer is gastric bleeding, which occurs when the ulcer reaches a gastric vessel and ruptures it.

For details, see Gastric ulcer.

Stomach cancer

Stomach cancer is one of the five most common types of cancer in women and men. It usually develops after years on the basis of a chronic gastric mucosal inflammation or a chronic gastric ulcer. Since the symptoms, such as bloody vomiting, swallowing disorders or weight loss, usually appear very late, the prognosis for the tumor is poor. Gastric cancer is usually treated first with chemotherapy and a subsequent (partial) removal of the stomach.

For details, see Stomach cancer.

Gastric bleeding

Gastric bleeding is a sometimes serious complication of various gastric diseases. It is an emergency and should be checked by a doctor immediately, as in extreme cases it can lead to death by bleeding to death. The majority of gastric bleeding (approx. 50%) is caused by a gastric ulcer. But also injuries to the gastric mucosa ("erosions") and gastric mucosal inflammation can lead to gastric bleeding. Stomach cancer should also always be excluded as a cause of gastric bleeding.
Severe gastric bleeding is usually diagnosed and treated by means of a gastroscopy, in which the source of the bleeding can be stopped.

For details, see Gastric bleeding.


Relux disease is widespread and affects around 20% of the population. Reflux is the Latin word for reflux. It is the leakage of stomach contents into the esophagus when the lower esophageal muscle does not close properly. Since the stomach's contents are acidic from the stomach acid, acidic burping, heartburn and pain behind the breast pectoral tend to occur with reflux. If the esophagus is exposed to acidic stomach contents over a longer period of time, it can lead to changes in the mucous membrane and complications such as esophagitis, a so-called "Barrett's syndrome" and, in the worst case, esophageal cancer.

For details, see Reflux.

Irritable stomach

The disease "irritable stomach" is a collective term for various disorders and complaints of the stomach for which no other organic cause can be found. Accordingly, the diagnosis is a diagnosis of exclusion. For example, the patients suffer from pain in the upper abdomen, bloating, nausea or vomiting. There is no drug therapy or surgery, but a change in lifestyle or diet can improve symptoms.

For details, see Irritable stomach.

Rare diseases of the stomach

Information on other rarer gastric diseases can be found here:

  • Gastrinoma
  • Zollinger-Ellison Syndrome
  • Gastric perforation

Diseases of the intestine

Gastrointestinal infection

Colloquially, an infection of the gastrointestinal tract with viruses or bacteria is referred to as gastrointestinal flu, medically as gastroenteritis. It is an inflammation of the lining of the gastrointestinal tract. Typically, the patients suffer from acute diarrhea and vomiting. Viral pathogens are much more common and fortunately safer than bacterial ones. The infection usually heals on its own, but under certain circumstances serious complications can arise.Elderly people and newborns in particular are at risk, as the water loss associated with diarrhea can lead to dehydration.

For more information, see Gastrointestinal infection.


Polyps occur in the gastrointestinal tract primarily in the large intestine. These are basically benign growths of the intestinal mucosa that arise from increased growth of these. They are particularly widespread in western countries, as their formation is favored by the intake of animal fats and proteins (i.e. meat). Polyps usually do not cause any symptoms, but can degenerate over the years and lead to colon cancer. It is therefore advisable to have regular colon cancer screening when you are older than 55 years. A colonoscopy is carried out during which the existing polyps can be assessed and removed if necessary.

See Colon Polyps for details.

Colon cancer

Colon cancer is the second most common cancer in both women and men and occurs mainly in old age. The colon section most frequently affected is the large intestine, but tumors are also possible in the small intestine. Intestinal tumors most often arise from degenerate colon polyps. The disease is symptom-free for a relatively long time; symptoms such as bloody stools or tarry stools only appear in later stages. Sudden constipation and diarrhea can also be signs of colon cancer.
The treatment usually involves surgically removing the part of the colon that contains the tumor. Chemotherapy and radiation also play an important role in therapy.

For details, see Colon cancer.

Crohn's disease

Crohn's disease is a chronic inflammatory bowel disease that primarily affects the small and large intestines. Theoretically, however, Crohn's disease can affect all sections of the digestive tract, e.g. also the esophagus. Inflammation foci of the mucous membrane occur, which can occur "discontinuously" in different places. The cause of the inflammatory reaction is still unclear; genetic and immunological factors are assumed. The patients suffer from having chronic abdominal pain, gas and diarrhea. In the treatment, drugs are used that inhibit the immune system and thus the inflammatory reaction (immunosuppressants).

For details, see Crohn's disease.

Ulcerative colitis

Another chronic inflammatory bowel disease is ulcerative colitis ("colitis" = inflammation of the colon). In contrast to Crohn's disease, ulcerative colitis is restricted to the large intestine and occurs continuously, that is to say at a single contiguous focus of inflammation. Symptoms include in turn, pain, gas, diarrhea and blood in the stool. The therapy is also similar to that of Crohn's disease, immunosuppressants are used as drugs that inhibit the immune system and the inflammatory reaction.

For details, see Ulcerative colitis.

Diverticulosis / diverticulitis

Colon diverticula are bulges in the intestinal lining. If such diverticula occur in several places in the large intestine, one speaks of diverticulosis. These bulges are completely symptom-free in the majority of patients (approx. 80%). Rare complications include Bleeding and a rupture of the intestinal wall. Diverticulosis is usually discovered by chance during colon cancer screening.
Intestinal contents can accumulate and become inflamed in the sacs. If such inflamed diverticula occur, one speaks of diverticulitis. This manifests itself in moderate to severe pain, signs of inflammation such as fever, diarrhea and much more. Uncomplicated diverticulitis can be treated with antibiotics, while complications such as a ruptured bowel or peritonitis require surgery.

For details, see Diverticulosis and Diverticulitis.

Meckel's diverticulum

Meckel's diverticulum is also a bulging of the intestine, but in the area of ​​the small intestine. What is special is that the diverticulum is formed on the basis of a remnant of the embryonic development. A connecting duct on the body of the embryo, the so-called yolk duct, does not close until birth but remains in place and the formation of Meckel's diverticulum can occur. This is usually noticed within the first 2 years of life and occurs about twice as often in boys as in girls. Since it is usually symptom-free for a very long time, it is only diagnosed in some patients at an advanced age. Inflammation of the Meckel's diverticulum, which symptomatically resembles appendicitis, can occur as a complication.

For details, see Meckel's diverticulum.

Irritable bowel syndrome

Irritable bowel syndrome is a chronic disease that has no organic cause. Digestive discomfort and sometimes severe pain occur, which persist for at least 3 months before the diagnosis can be made. Similar to the irritable stomach, it is a diagnosis of exclusion. Patients also typically experience gas and diarrhea. Since no clear cause is known, there is unfortunately no specific therapy. Certain eating habits and drugs that protect the intestinal lining can improve the situation.

For details, see Irritable bowel syndrome.

Celiac disease

Celiac disease is a gluten intolerance. Gluten is a protein found in many grains. It is found in wheat, barley, rye, oats and spelled, among others. Celiac disease is an autoimmune disease in which the body makes antibodies that react with gluten and cause inflammation (gliadin antibodies). Celiac disease is diagnosed by means of a gastroscopy, which also shows the small intestine. There are changes in the mucous membrane. Patients should only consume gluten-free foods, e.g. in the form of potatoes, corn, rice, millet and soy.

For details, see Celiac disease.

Rare diseases of the intestine

You can find information on other rarer diseases of the intestine at:

  • Bowel abscess
  • Mesenteric artery occlusion
  • Whipple's disease
  • Pseudomembranous colitis

Other diseases of the gastrointestinal tract

Peritonitis / peritonitis

The peritoneum lines the inside of the abdominal cavity and thus has external contact with the abdominal organs. Peritonitis (Peritonitsi) is a serious illness that should definitely be treated as an inpatient, as it can be fatal. It occurs when pathogens in the gastrointestinal tract leave it and pass into the free abdominal cavity. Most often this happens in the context of appendicitis, especially when it comes to a ruptured appendix. Even after operations on organs in the abdominal cavity, leaks in the seams can cause pathogens to penetrate the abdominal cavity.

For details, see Peritonitis.

Inflammation of the pancreas / pancreatitis

The pancreas produces important nutritional hormones, such as insulin, and shares a duct with the gallbladder. Therefore, diseases of the gallbladder, such as gallstones, can lead to inflammation of the pancreas (Pancreatitis) come. Excessive alcohol consumption is also a major trigger. Overall, inflammation of the pancreas is a very serious disease that should be treated as an inpatient. Typical symptoms are belt-shaped upper abdominal pain, nausea and vomiting.

For details, see Inflammation of the pancreas.