Ulcerative colitis - causes, symptoms, diagnosis, treatment, pathology

Summary

Ulcerative colitis, the most common form of inflammatory bowel disease, causes ulcers and inflammation in the large intestine, including the colon and rectum. Though initially thought to be linked to diet and stress, it's now considered an autoimmune disorder. T cells attack the intestinal lining, leading to tissue damage. The disease often leads to painful symptoms, including diarrhea with blood. Diagnosis involves colonoscopy and imaging, while treatment ranges from anti-inflammatory medications to surgery in severe cases. The condition is more common among young women and those with a family history.

Takeaways

• 🦠 Inflammatory bowel disease (IBD) causes inflammation in the small and large intestines, with ulcerative colitis being a common type that specifically affects the colon and rectum.
• 💢 Ulcerative colitis leads to ulcers forming on the inner surface (mucosa) of the large intestine, resulting in open sores and tissue erosion.
• 🔄 The disease progresses in cycles of flare-ups, where new damage occurs, and remissions, during which tissue begins to heal.
• 🧬 Unlike Crohn’s disease, ulcerative colitis affects only the mucosa and submucosa layers of the large intestine and occurs in a continuous pattern without healthy tissue in between.
• ⚔️ The condition is thought to be autoimmune in nature, with cytotoxic T cells attacking the epithelial lining of the colon.
• 🧫 Some patients produce p-ANCAs (perinuclear antineutrophil cytoplasmic antibodies), which may cross-react with neutrophils due to similarities between bacterial and human cell structures.
• 🧪 Environmental factors like sulfide-producing gut bacteria, combined with genetic predisposition, likely contribute to the development of ulcerative colitis.
• 👩‍⚕️ Ulcerative colitis is more common among young women (teens to 30s), especially those of Caucasian or Eastern European Jewish descent.
• 💩 Key symptoms include left lower quadrant abdominal pain, frequent diarrhea, and blood in the stool due to mucosal damage and impaired water absorption.
• 🩺 Diagnosis is typically made via colonoscopy and biopsy, supported by imaging tests like CT scans, MRI, or barium enema.
• 💊 Treatment ranges from anti-inflammatory drugs (e.g., mesalamine) to immunosuppressants (e.g., corticosteroids) and biologics (e.g., infliximab); colectomy may be required in severe cases.
• 🫀 Surgical removal of the colon (colectomy) effectively cures ulcerative colitis since the disease only affects the large intestine, though it results in complete loss of colon function.

Q & A

What is inflammatory bowel disease (IBD)?

Inflammatory bowel disease (IBD) refers to inflammation in the small and large intestines, which can lead to various digestive issues. The inflammation typically affects the bowel, resulting in pain, diarrhea, and other symptoms.

What is colitis, and how does it relate to IBD?

Colitis specifically refers to inflammation in the colon, or large intestine, and is a subset of inflammatory bowel disease (IBD). It is a condition where the colon becomes inflamed, causing symptoms like abdominal pain and diarrhea.

What distinguishes ulcerative colitis from other types of IBD?

Ulcerative colitis is a type of IBD that affects only the large intestine, causing inflammation and ulcers along its inner surface. It typically involves the colon and rectum and is marked by continuous, circumferential inflammation, unlike Crohn’s disease, which can affect any part of the gastrointestinal tract.

What are the ulcers associated with ulcerative colitis?

In ulcerative colitis, ulcers are open sores or breaks in the mucosal lining of the colon and rectum, caused by the destruction of the epithelial cells. These ulcers can lead to pain, bleeding, and digestive problems.

What are the environmental factors thought to contribute to ulcerative colitis?

Environmental factors like diet and stress were previously thought to be major contributors to ulcerative colitis. However, it is now understood that while these factors can worsen symptoms, the disease is primarily autoimmune in nature.

How is the immune system involved in the development of ulcerative colitis?

Ulcerative colitis is considered an autoimmune disease. It is believed that cytotoxic T cells in the immune system attack the epithelial cells lining the colon, causing inflammation and ulceration. These T cells might target gut bacteria that resemble human cells.

What role do p-ANCAs play in ulcerative colitis?

P-ANCAs (perinuclear antineutrophilic cytoplasmic antibodies) are antibodies found in the blood of some ulcerative colitis patients. These antibodies may indicate an immune response to gut bacteria that share structural similarities with the body's own cells, possibly contributing to the disease.

What are the symptoms of ulcerative colitis?

Common symptoms of ulcerative colitis include abdominal pain (especially in the left lower quadrant), diarrhea (often with blood in the stool), and weight loss. The condition can also lead to dehydration due to the impaired absorption of water in the large intestine.

How is ulcerative colitis diagnosed?

Diagnosis of ulcerative colitis typically involves a colonoscopy, where a camera is inserted into the colon to view the ulcers directly. Other diagnostic tools may include a barium enema, CT scans, and MRIs to detect abnormalities.

What are the main treatment options for ulcerative colitis?

Treatment for ulcerative colitis depends on the severity of symptoms and may include anti-inflammatory medications like sulfasalazine, immune-suppressing drugs such as corticosteroids, and biologic treatments like infliximab. In severe cases, surgery to remove the colon (colectomy) may be necessary.

What happens if ulcerative colitis is left untreated?

If left untreated, ulcerative colitis can lead to complications like severe dehydration, malnutrition, colon perforation, and even colon cancer in long-term cases. Early diagnosis and treatment are crucial to prevent these serious outcomes.

How does the pattern of ulceration in ulcerative colitis affect the body?

In ulcerative colitis, the ulceration pattern is continuous and circumferential, meaning the inflammation spreads around the entire colon, starting from the rectum. This continuous damage affects the bowel's ability to absorb water, leading to diarrhea and other digestive issues.