Ulcerative colitis – Inflammation of the large intestine in chronic inflammatory bowel disease

Ulcerative colitis and Crohn’s disease are chronic, typically relapsing-remitting inflammations of the lining of the large intestine. Both conditions are classified as chronic inflammatory bowel diseases.

Crohn’s disease usually affects the small intestine, but it can also occur anywhere along the gastrointestinal tract. Ulcerative colitis, on the other hand, occurs only in the large intestine. The inflammation usually begins in the rectum. It then often spreads first to the left side of the colon and, in some cases, to the entire colon. It very rarely spreads to the small intestine.

Ulcerative colitis, just like Crohn’s disease, is an inflammatory bowel disease © bilderzwerg | AdobeStock

Ulcerative colitis is one of the most common chronic inflammatory bowel diseases: Out of every 100,000 people, approximately 120 to 200 suffer from ulcerative colitis.

In Central Europe, between 5 and 10 people per 100,000 residents are diagnosed with ulcerative colitis each year.

In principle, the disease can occur at any age. However, young adults between the ages of 15 and 30 are most commonly affected by ulcerative colitis.

In about 25 percent of all those affected, the first symptoms appear before the age of 20, and in rare cases even during infancy. Ulcerative colitis occurs slightly more frequently in women than in men.

The causes of ulcerative colitis are unknown. However, given the familial clustering of the disease, it is believed that there is a genetic predisposition.

Furthermore, disorders of the immune system can lead to pathological interactions with the intestinal mucosa and to inflammation in the large intestine.

Other causes include:

• Psychosomatic factors (e.g., psychological strain, stress)
• Dietary factors
• Viruses and bacteria

The diagnosis of ulcerative colitis usually begins with a discussion of current symptoms and medical history (anamnesis). This is followed by a physical examination.

Additional tests may include:

• Colonoscopy to visually examine the colon and take tissue samples from the colon lining
• Blood tests to measure inflammatory markers to rule out a bacterial infection
• Stool analysis to rule out infectious bowel inflammation
• Ultrasound (sonography) to provide an overview of the anatomical structure of the abdominal cavity
• X-ray contrast study to better assess the large intestine
• A rectal endoscopy (rectoscopy) is required prior to scheduled surgery for ulcerative colitis.

A colonoscopy allows for a detailed examination of the intestine © phonlamaiphoto | AdobeStock

Ulcerative colitis is typically characterized by cramping abdominal pain, usually:

• in the lower left abdomen
• in the center of the lower abdomen, or
• in the lower back

Patients often experience pain before or immediately after a bowel movement.

Furthermore, this intestinal disease is characterized by bloody and mucous, and sometimes watery, diarrhea.

The frequency of diarrhea depends directly on how severely the large intestine is affected by the disease. Diarrhea can occur up to 20 times a day and, in severe cases, even up to 30 times a day.

Depending on the severity, other symptoms of ulcerative colitis may occur:

• Exhaustion, physical weakness, fatigue
• Loss of appetite and nausea
• Anemia
• Fever
• Weight loss
• Increase in white blood cells (leukocytosis)

The disease typically follows a chronic, relapsing course, but it can also have a more constant course.

Thus, three forms can be distinguished:

1. Chronic-recurrent ulcerative colitis

This is the most common form, affecting about 85 percent of patients. The intestinal disease progresses in flare-ups with periods without symptoms that can last up to several years. However, these periods may be followed by recurrent relapses.

2. Chronic-continuous ulcerative colitis

This form occurs in about 10 percent of patients. Those affected suffer from symptoms continuously and do not experience symptom-free periods.

3. Acute fulminant ulcerative colitis

About 5 percent of patients suffer from this form.

This form is characterized by a very sudden and severe onset of the disease.

Symptoms include:

• Severe diarrhea
• Abdominal pain and
• Fever

Depending on the extent and duration of the inflammation, complications may arise. However, most patients do not experience complications. The occurrence of a complication is often an indication for ulcerative colitis surgery.

The most important complications of ulcerative colitis affecting the large intestine are:

• Toxic megacolon: an overdistended large intestine caused by weakened walls and gas accumulation.
• Bowel perforation: A bowel perforation caused by ulcerative colitis is a life-threatening complication that requires immediate surgery.
• Severe intestinal bleeding: Blood transfusions can often compensate for blood loss. Surgical removal of the affected section of the intestine is rarely necessary in cases of ulcerative colitis.
• Scarring (strictures): Scarring can lead to a narrowing of the bowel and an intestinal obstruction, which requires immediate surgery.
• Fistulas and abscesses
• Colon cancer: Patients with ulcerative colitis have an increased risk of colon cancer. The risk rises significantly as the duration of the disease increases. For example, after 25 years of the disease, the risk is about 40 percent.

Ulcerative colitis can also cause colorectal cancer © peterschreiber.media | AdobeStock

The most important complications of ulcerative colitis outside the colon are:

• Inflammation of the eye
• Inflammation of the bile ducts
• Joint pain, joint inflammation
• Liver damage
• Painful skin lesions (erythema nodosum)

Since the causes of ulcerative colitis are unknown, there is no cure. Therefore, treatment aims to relieve symptoms and reduce the risk of complications.

Depending on the severity and course of the disease, there are generally several treatment options available for ulcerative colitis:

• For mild cases: Typically, medication (e.g., immunosuppressants, cortisone, 5-aminosalicylic acid) and dietary changes
• In severe cases: Surgical treatment (ulcerative colitis surgery) if complications arise or if drug therapy is insufficiently effective

What is ulcerative colitis, and how does it differ from Crohn’s disease?

Ulcerative colitis is a chronic inflammatory bowel disease that affects only the large intestine. Unlike Crohn’s disease, which can affect any part of the intestine, ulcerative colitis involves continuous inflammation of the intestinal lining. Like Crohn’s disease, ulcerative colitis is a chronic inflammatory bowel disease.

What are the typical symptoms of ulcerative colitis?

Typical symptoms of ulcerative colitis include diarrhea—often containing blood and mucus—as well as abdominal pain. Acute symptoms may occur during a flare-up of ulcerative colitis. Other symptoms may include fever, weight loss, or joint pain.

How is ulcerative colitis diagnosed?

The diagnosis of ulcerative colitis is made clinically based on medical history, laboratory tests, and a colonoscopy. During the colonoscopy, inflammation of the intestinal lining is observed in the rectum and colon. Gastroenterologists follow current guideline recommendations.

What treatment is used for ulcerative colitis?

Ulcerative colitis is typically treated with medication, such as mesalazine or immunosuppressive drugs. In cases of severe, active ulcerative colitis, immunosuppressive therapy may be necessary. In rare cases, surgical treatment involving the removal of the large intestine is required.

What complications can occur?

Complications of ulcerative colitis can include colorectal cancer or toxic megacolon. Chronic inflammation is associated with an increased risk of colorectal cancer. Consistent treatment and regular colonoscopies reduce this risk.