Digestive Disorders > Lower Abdomen

Intestinal inflammation: All you need to know

Dr. med. Andre Sommer

Dr. med. Andre Sommer

Abdominal pain and indigestion are the most common intestinal inflammation symptoms. About 1 in 10 people regularly suffers from these, and in many cases an inflammation in the intestine is the cause.

What is intestinal inflammation?

Inflammation is the body's reaction to harmful stimuli. The blood circulation is stimulated and messenger substances are released, which then attract immune cells. This is how the body prepares to ward off and repair the damage.

When inflammation occurs in the intestine, it usually affects the mucous membrane (this is the layer that lines the inside of the intestinal wall). The cells of the mucous membrane are constantly exposed to external stimuli, for example from food components, bacteria, viruses, fungi, or other intruders. Although the mucous membrane itself is very robust, inflammation can be triggered by such stimuli. Since the intestine has its own immune defense, this often results in a pronounced reaction.

Where can inflammation occur in the intestine?

Theoretically, the entire intestine (i.e. small and large intestine) can be affected by inflammation. But it rarely happens that the full length of the intestine is affected. Depending on the cause of the inflammation, certain sections of the intestine are mostly affected.

The inflammatory bowel disease ulcerative colitis, for example, only occurs in the large intestine. It almost always starts from the last section of the intestine (the rectum), but it can also affect the entire colon. Intestinal inflammation caused by viruses, however, mainly affects the small intestine and stomach; this is referred to as gastroenteritis.

What causes intestinal inflammation?

There are many causes of intestinal inflammation. Pathogens such as viruses, bacteria, and fungi can penetrate the intestine from the outside and cause inflammation. Certain eating habits can affect the natural intestinal flora, promoting inflammation. When the immune system attacks the intestine, it is referred to as an autoimmune disease. The inflammatory bowel diseases Crohn's disease and ulcerative colitis have such an autoimmune cause.

Viruses, bacteria, and fungi

Viruses are the most common cause of intestinal inflammation. It is believed that they are responsible for inflammation of the gastrointestinal tract (gastroenteritis) in up to 70 percent of cases. Depending on the virus, intestinal inflammation can be accompanied by severe symptoms, often also by vomiting and fever. Viruses usually heal without medication. In the event of gastroenteritis, it is important to ensure adequate hydration.

Bacterial inflammation is less common than viral inflammation. It is usually accompanied by more severe and longer-lasting complaints and in many cases requires inpatient hospital treatment. Antibiotics can be used to treat bacterial inflammation.

The yeast candida albicans plays an important role in inflammation of the intestine caused by fungi. Although it also occurs in healthy people on the intestinal mucosa (colonisation), it can also multiply drastically and break the mucosal barrier. Then an infection occurs. However, this rarely happens and generally occurs in people with impaired immune systems.

Chronic inflammatory bowel disease

Crohn's disease and ulcerative colitis are chronic inflammatory bowel diseases. These are diseases in which one’s own immune system targets parts of the intestine. The exact causes of this immune system reaction are not yet sufficiently understood. However, it is known the inflammatory bowel diseases differ in where they occur in the gastrointestinal tract.

Theoretically, Crohn's disease can affect the entire digestive tract from the mouth to the anus, while omitting individual sections. Ulcerative colitis, on the other hand, only occurs in the large intestine and only continuously, that is, without omitting parts of the intestine.

Can an improper diet lead to intestinal inflammation?

The human intestine is home to around 40 trillion bacteria. This corresponds to a weight of around 200 g (7 oz). This intestinal flora is designed to live with us. It processes components of our food and helps us to gain important nutrients, such as short-chain fatty acids and vitamins.

Our diet and our intestinal flora influence each other. Depending on what we eat, we also use it to attract other types of bacteria. Sugary foods attract sugar-processing bacteria and fungi. Fiber-rich food feeds fiber-processing bacteria.

To keep harmful bacteria at bay, it is important to keep intestinal flora balanced. The bacteria that form part of a healthy and natural intestinal flora prevent harmful bacteria from spreading and multiplying. A healthy intestinal flora prevents inflammation in the intestine.

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What are the symptoms of intestinal inflammation?

The symptoms of intestinal inflammation are diverse and can vary from patient to patient. One common symptom that occurs in many patients with intestinal inflammation is diarrhea. The damage causes the mucous membrane to lose its ability to extract water from food. The result is that the contents of the intestine remain fluid and leave the intestines faster than in healthy people.

Diarrhea is often accompanied by severe abdominal pain and cramps. Depending on the cause of the inflammation of the bowel, the pain occurs in various places in the abdomen. With classic gastroenteritis, the entire stomach usually hurts. Ulcerative colitis mainly affects the rectum and is often accompanied by pain in the left lower abdomen.

Inflammation of the intestine often leads to nausea and vomiting. On the one hand, this complicates food intake and, on the other hand, vomiting (often in combination with diarrhea) leads to dehydration. This is why it is important to ensure you drink sufficient amounts of fluids in the event of inflammation of the intestine.

Especially with viral and bacterial inflammation, general symptoms such as fatigue, fever, headache, and body aches often occur.

The most common symptoms of intestinal inflammation are:

  • Diarrhea
  • Nausea and vomiting
  • Severe abdominal pain and cramps
  • Fatigue, headache, and body aches.

Is inflammation in the intestine without diarrhea possible?

Diarrhea is a common symptom of intestinal inflammation, but not every case of intestinal inflammation is accompanied by diarrhea. Diarrhea occurs when the damaged mucous membrane can no longer properly absorb the fluid in the intestine. Certain substances that are released by bacteria, for example, can also hinder fluid absorption.

But while diarrhea occurs in many intestinal infections, there are also cases in which this is not the case. Mild gastrointestinal inflammation often leads to little or no changes in stool frequency and consistency.

The chronic inflammatory bowel diseases Crohn's disease and ulcerative colitis are usually accompanied by diarrhea. But here too there can be phases in which pain occurs but the diarrhea is absent.


Did you know?

Diarrhea is a common symptom of intestinal inflammation, but diarrhea does not necessarily occur in every case of intestinal inflammation.


How is inflammation in the intestine diagnosed?

There are several diagnostic tools to diagnose intestinal inflammation. Viral gastroenteritis, which accounts for a large part of the intestinal inflammation, can already be recognized from the patient's descriptions. Examination of a stool sample is not necessary with common viral gastroenteritis.

In more complex cases or if bacteria are suspected to be the cause, testing a stool sample can be useful. Blood tests can also help determine the extent of the inflammation.

If no diagnosis can be made with these remedies, a colonoscopy can be done. Most intestinal inflammation can be diagnosed with this method.

Do ultrasounds help to diagnose inflammation in the intestine?

An ultrasound examination makes it possible to display structures inside the body without radiation. In the area of the gastrointestinal tract, ultrasound is used, for example, to diagnose appendicitis. However, ultrasound examinations are only of limited use for the diagnosis of intestinal inflammation. The reason is that they may reveal gross signs of inflammation, but it is difficult to determine the exact extent of the inflammation and its cause.

In addition, ultrasound is a procedure that is heavily dependent on the respective examiner: The more the examiner specializes in the ultrasound of intestinal diseases, the sooner they will be able to diagnose intestinal inflammation with this method.

How can you treat intestinal inflammation?

The most common type of intestinal inflammation, viral gastroenteritis, usually heals without treatment. The most important measures here are bed rest and adequate fluid intake. The best fluids are water, tea, and clear broths, such as vegetable or chicken broth. These broths also contain important minerals, which the body may also lack due to the intestinal inflammation.

In the case of severe diarrhea or special patient groups such as old people or small children, a so-called Oral Rehydration Solution from the pharmacy is important to supply minerals (electrolytes). What the right diet looks like varies from person to person.

Taking antibiotics does not make sense for intestinal inflammation caused by viruses, since antibiotics only work against bacteria. Bacterial intestinal inflammation heals spontaneously in some cases, in which case the treatment is the same as with viral inflammation of the intestine. In some cases, antibiotics can also be helpful.

In the event of intestinal inflammation caused by an imbalance in the intestinal flora (dysbiosis), nutrition is an important part of the therapy. This is because patients can actively promote the growth of “good” bacteria through a healthy, high-fiber diet. If enough of these “health aids” are present, this also prevents harmful bacteria from growing.

Inflammatory bowel diseases are treated in stages. Medicines that suppress the immune system and thus keep the body's reaction at bay are primarily used for this. These drugs include, for example, cortisone, which is used to treat acute flare-ups.

Intestinal inflammation is common. In order to deal with the symptoms in an optimal way, it is important to understand the triggers and typical symptoms of intestinal inflammation, since there are many different treatment methods available, depending on the cause.

Forbes A, Escher J, Hebuterne X, et al. ESPEN guideline: Clinical nutrition in inflammatory bowel disease. _Clin Nutr. _2017;36(2):321-347.

Hagel S, Epple HJ, Feurle GE, et al. [S2k-guideline gastrointestinal infectious diseases and Whipple's disease]. _Z Gastroenterol. _2015;53(5):418-459

Jameson JL, Fauci AS, Kasper DL, Hauser SL, Longo DL, Loscalzo J, eds. Harrison’s Principles of Internal Medicine. 20th Revised ed. New York, NY: McGraw-Hill Education, 2018.

Posovszky C, Backendorf V, Buderus S, et al. _Z Gastroenterol. _2019;57(9):1077-1118

Sender R, Fuchs S, Milo R. Revised Estimates for the Number of Human and Bacteria Cells in the Body. _PLoS Biol. _2016;14(8):e1002533.

Dr. med. Andre Sommer

Dr. med. Andre Sommer

I’m André, a medical doctor from Berlin. Together with a team of medical doctors, nutritionists and data scientists we empower people to understand digestive issues with our app Cara.

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