Intestinal Inflammation: What It Is, Types, and Inflammatory Diseases

The word "inflammation" in conversations about the intestines has become almost universal: it is used to explain post-meal heaviness, bloating, and low mood. In reality, different conditions lie behind this word, and not every redness of the mucosa is a disease. Let us clarify what an inflamed intestine means from a medical point of view and how inflammatory bowel diseases differ.

What intestinal inflammation is

Inflammation is a tissue reaction to damage or an attack by the immune system. Inflammatory bowel diseases (IBD) is an umbrella term for conditions that cause severe abdominal pain and diarrhea. These are long-term diseases, but there are methods that help manage the symptoms. The exact cause of IBD is unknown: it is believed that the immune system attacks the intestine itself, and it becomes inflamed. The risk is higher if a close relative — parents, brothers, sisters, grandmothers, or grandfathers — already has such a disease.

Inflammation of the small and large intestine: how they differ

The small intestine is a long tube where nutrients are absorbed; the large intestine (colon) is the section where stool is formed. Crohn's disease can cause ulcers and inflammation anywhere in the digestive tract, from the mouth to the anus, but most often affects the small intestine and the beginning of the large intestine. Ulcerative colitis affects the rectum and colon. Microscopic colitis is also localized in the colon. In ulcerative colitis, the rectum is always involved, and the inflammation has a diffuse continuous character.

Inflammatory bowel diseases: Crohn's disease and ulcerative colitis

Crohn's disease is a chronic disease in which inflammation can occur in any part of the digestive tract. It can lead to complications: intestinal obstruction, fistulas, abscesses, anal fissures, ulcers, malnutrition, as well as inflammation of the joints, eyes, and skin. Ulcerative colitis is a chronic autoimmune inflammation of the colonic mucosa with flare-ups. It occurs in 35–100 people per 100,000 population, that is, in less than 0.1% of the population.

Autoimmune diseases of the intestine

In an autoimmune reaction, the immune system attacks the body's healthy cells. Researchers believe that this is the mechanism that may underlie Crohn's disease. In ulcerative colitis, inflammation arises from the interaction of genetic factors and environmental factors. Smoking approximately doubles the risk of Crohn's disease. Stress and certain foods do not cause the disease but can worsen symptoms.

Main symptoms of an inflamed intestine

The main signs of IBD are diarrhea lasting longer than 4 weeks, abdominal pain, blood or mucus in the stool, rectal bleeding, constant fatigue, and effortless weight loss. In ulcerative colitis, there may be frequent loose stools with blood or mucus, abdominal pain, weight loss, and fatigue. Extraintestinal manifestations are also possible: lesions of the skin, oral mucosa, eyes, and joints.

• Diarrhea lasting longer than 4 weeks
• Blood or mucus in the stool
• Constant fatigue and weight loss
• Abdominal pain that does not go away

How inflammation is diagnosed and when to see a doctor

The doctor takes a medical history and family history, performs an abdominal examination, and orders blood and stool tests. Colonoscopy, upper endoscopy, CT, and barium X-ray are used. In ulcerative colitis, blood tests show signs of inflammation and anemia, and a biochemical blood test shows elevated C-reactive protein. You should see a doctor if diarrhea lasts longer than 7 days, if pain or bloating does not go away or returns, if there is blood or mucus in the stool, or if there is unexplained weight loss.

Intestinal inflammation by itself is not a reason to call an ambulance; 103 or 112 — if abdominal pain is very severe, rectal bleeding does not stop, there is a lot of blood or large clots in the stool, or vomiting of blood has begun or the vomit looks like coffee grounds or soil.

This material is for reference: it helps to understand the terms but does not replace a doctor's consultation — only a specialist can assess your situation as a whole.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer