Colitis and ulcerative colitis are both types of inflammatory bowel disease (IBD) that cause inflammation and ulcers in the digestive tract. However, there are some key differences between the two conditions.
Definitions
Colitis is a general term that refers to inflammation of the colon. There are several types of colitis, including:
- Infectious colitis – caused by bacterial, viral or parasitic infections
- Ischemic colitis – caused by reduced blood flow to the colon
- Chemical colitis – caused by reactions to medications or toxins
- Radiation colitis – caused by radiation therapy
- Microscopic colitis – inflammation is only visible under a microscope
Ulcerative colitis is a specific type of inflammatory bowel disease that only affects the colon (large intestine) and rectum. It is characterized by ulcers and inflammation in the innermost lining of the colon and rectum.
Prevalence
Ulcerative colitis is one of the most common forms of colitis. According to the Crohn’s and Colitis Foundation, ulcerative colitis affects about 907,000 adults and children in the United States. This equals about 0.3% of the U.S. population.
Other types of colitis are less common. For example, infectious colitis accounts for less than 5% of cases of acute diarrhea in Western countries. Microscopic colitis has a prevalence of about 103 per 100,000 people.
Causes
The causes of colitis depend on the specific type:
- Infectious colitis is caused by bacteria, viruses, or parasites
- Ischemic colitis is caused by decreased blood flow to the colon
- Chemical colitis is caused by reactions to medications or toxins
- Radiation colitis is caused by radiation therapy
- Microscopic colitis does not have a known cause
In contrast, the exact cause of ulcerative colitis is unknown. However, experts believe it involves an abnormal response by the body’s immune system. Genetics, environment, and gut bacteria may play a role.
Symptoms
Common symptoms of colitis include:
- Diarrhea
- Abdominal pain and cramping
- Blood or pus in the stool
- Urgency to have a bowel movement
- Fever (in infectious colitis)
- Weight loss
Symptoms of ulcerative colitis include:
- Diarrhea
- Abdominal pain and cramping
- Rectal pain
- Blood in the stool
- Urgency to have a bowel movement
- Incomplete evacuation of stool
- Fatigue
- Weight loss
Ulcerative colitis symptoms tend to be more severe than other forms of colitis. Symptoms may also develop gradually over time, rather than come on suddenly.
Location of Inflammation
Most types of colitis can occur in any part of the colon. However, the location of inflammation differs between ulcerative colitis and other forms of colitis:
- Ulcerative colitis always affects the innermost lining of the colon and rectum
- Other forms of colitis can affect deeper layers of the colon wall
Ulcerative colitis also nearly always involves the rectum (known as proctitis) and may extend proximally in a continuous manner. Other types of colitis typically have patchy or segmental areas of inflammation.
Diagnosis
Colitis may be diagnosed through:
- Medical history and physical exam
- Stool culture or exam for blood, bacteria, or parasites
- Blood tests for infection or inflammation
- Colonoscopy with biopsies
- CT scan or X-ray
Diagnosing ulcerative colitis involves similar tests, but biopsy results are most important. Biopsies from a colonoscopy allow doctors to confirm inflammation and rule out other types of colitis.
Treatment
Treatment for colitis depends on the underlying cause and may include:
- Antibiotics for infectious colitis
- Discontinuing medications causing chemical colitis
- IV fluids and electrolyte replacement
- Medications to reduce inflammation like 5-ASAs, steroids, or immunomodulators
- Surgery in severe or chronic cases
Ulcerative colitis treatment typically involves medications to reduce inflammation and suppress the immune system. The main medications used are:
- 5-ASAs (mesalamine)
- Corticosteroids
- Immunomodulators
- Biologics (TNF inhibitors)
About 20-30% of ulcerative colitis cases require surgery to remove the colon (colectomy) if medications are ineffective.
Complications
Complications of colitis include:
- Dehydration
- Malnutrition
- Perforation of the colon
- Strictures or narrowing of the colon
- Bowel obstruction
- Severe bleeding
- Increased risk of colon cancer (with some types)
Complications of ulcerative colitis include:
- Severe internal bleeding
- Rupture of the colon
- Increased risk of colon cancer
- Liver disease (primary sclerosing cholangitis)
- Joint pain and swelling
- Osteoporosis
- Anemia
Ulcerative colitis has several unique extraintestinal complications not seen with other forms of colitis. The reason for this difference is unknown.
Summary of Differences
| Colitis | Ulcerative Colitis | |
|---|---|---|
| Definition | General term for colon inflammation | Specific type of inflammatory bowel disease |
| Prevalence | Varies depending on type | About 0.3% of U.S. population |
| Causes | Varies (infections, ischemia, radiation, etc.) | Unknown; believed to be immune-mediated |
| Location | Can be patchy inflammation | Continuous inflammation of colon and rectum lining |
| Diagnosis | Endoscopy, stool culture, imaging tests | Colonoscopy with biopsies |
| Treatment | Cause-specific (antibiotics, discontinuing medications, etc.) | Medications to reduce inflammation; surgery if severe |
| Complications | Dehydration, perforation, strictures, bleeding, increased cancer risk | Severe bleeding, colon rupture, arthritis, liver disease, increased cancer risk |
Key Points
- Colitis refers to inflammation of the colon from any cause, while ulcerative colitis is a specific type of inflammatory bowel disease.
- Ulcerative colitis involves continuous inflammation of the colon and rectum lining, while colitis can be patchy.
- Ulcerative colitis has a number of extraintestinal manifestations not seen in other forms of colitis.
- While colitis has many potential causes, the exact cause of ulcerative colitis is unknown.
- Both conditions share some common symptoms like diarrhea and abdominal pain, but ulcerative colitis symptoms tend to be more severe.
Conclusion
In summary, ulcerative colitis is a distinct condition and not interchangeable with the term “colitis.” While ulcerative colitis is a type of colitis characterized by inflammation of the colon, it differs from other forms of colitis in its continuous location, unknown cause, and associated complications. Both ulcerative colitis and other types of colitis share similar symptoms of diarrhea, abdominal pain, and bleeding, but ulcerative colitis tends to cause more severe inflammation and symptoms. Accurate diagnosis is important, as treatment options can vary depending on the specific type of colitis.