Ulcerative colitis overview

# Overview
Ulcerative colitis (Colitis ulcerosa, UC) is a form of inflammatory bowel disease (IBD). Ulcerative colitis is a form of colitis, a disease of the intestine, specifically the large intestine or colon, that includes characteristic ulcers, or open sores, in the colon. The main symptom of active disease is usually diarrhea mixed with blood, of gradual onset. Ulcerative colitis is, however, a systemic disease that affects many parts of the body outside the intestine. Because of the name, IBD is often confused with irritable bowel syndrome ("IBS"), a troublesome, but much less serious condition. Ulcerative colitis has similarities to Crohn's disease, another form of IBD. Ulcerative colitis is an intermittent disease, with periods of exacerbated symptoms, and periods that are relatively symptom-free.  Although the symptoms of ulcerative colitis can sometimes diminish on their own, the disease usually requires treatment to go into remission.

# Historical Perspective
The first case of ulcerative colitis was reported by Sir Samuel Wilks in 1859. He even coined the term ulcerative colitis and submitted the histopathological slides for the first time in his case report. It was believed that Prince Charles, Young Pretender of the roman empire, suffered from ulcerative colitis and cured himself by adopting a milk-free diet. In 1885, Allchin gave a detailed description of ulcerative colitis for the first time. Based on the work by Allchin, Hale-White in 1888, differentiated ulcerative colitis from Crohn's disease.

# Classification
The inflammatory bowel disease (IBD) is divided primarily into ulcerative colitis and Crohn's disease. Some cases which depict overlapping features of both ulcerative colitis and Crohn's disease can be classified as intermediate colitis. Depending on the location of involved are with respect the descending colon, ulcerative colitis can be classified as proximal or distal. Based on the severity, ulcerative colitis can be classified into mild, moderate, severe or fulminant.

# Pathophysiology
Ulcerative colitis is characterized by inflammation of the mucosa which is diffuse and primarily confined to the colon. The disease can extend proximally in a continuous, circular and uniform manner. Various factors influencing the pathogenesis of ulcerative colitis including intestinal micro bacteria, genetics, immunological abnormalities, and environmental factors.

# Causes
The exact cause of ulcerative colitis is still unknown. Several possible causes have been suggested including genetic, environmental and autoimmune factors.

# Differentiating Ulcerative Colitis from other Diseases
Ulcerative colitis should be differentiated from other causes of diarrhea. It is very important to differentiate it from Crohn's disease as the management of both conditions is different though the initial presentation may be confused for any of these disorders.

# Epidemiology and Demographics
United States, Canada, the United Kingdom, and Scandinavia have the highest incidence of inflammatory bowel disease i.e ulcerative colitis and Crohn's disease.The incidence of ulcerative colitis in North America is 10-12 cases per 100,000. With highest incidences in the United States, Canada, the United Kingdom, and Scandinavia. Higher incidences are seen in northern locations compared to southern locations in Europe and the United States.

# Risk Factors
Risk factors include a family history of ulcerative colitis, or Jewish ancestry. It may affect any age group, although there are peaks at ages 15 - 30 and then again at ages 50 - 70. It affects men and women equally and appears to run in families, with reports of up to 20 percent of people with ulcerative colitis having a family member or relative with ulcerative colitis or Crohn's disease. A higher incidence of ulcerative colitis is seen in Whites and people of Jewish descent.

# Screening
Patients with ulcerative colitis require screening for colorectal carcinoma. The United States Preventive Task Force (USPSTF]) in patients without ulcerative colitis recommends screening for colorectal carcinoma starting at age 50 and ending at 75. In case of a patient with ulcerative colitis, the risk of colorectal carcinoma is increased and so the American Cancer Society recommends having the initial screening 8 years after the patient is diagnosed with severe disease, or when most of, or the entire, large intestine is involved and 12 - 15 years after diagnosis when only the left side of the large intestine is involved.

# Natural History, Complications and Prognosis
Patients with ulcerative colitis experience intermittent symptoms. This means that there are periods of disease inactivity alternating with "flares" of disease. Anemia, bowel perforation, toxic megacolon and colorectal carcinoma are a few known complications of ulcerative colitis. Ulcerative colitis also has a significant association with primary sclerosing cholangitis (PSC). A permanent and complete cure from ulcerative colitis is unusual.

# Diagnosis

## History and Symptoms
Patients with ulcerative colitis present with a history of bloody diarrhea mixed with mucus, of gradual onset. Some patients may present with a sudden attack of diarrhea, fever and abdominal pain. The extra intestinal symptoms may include joint swelling and pain, inflammation of the eye and skin involvement.

## Physical Examination
Ulcerative colitis shows intestinal and extra intestinal findings on physical examination. These include abdominal tenderness, fever, pallor, inflammation of the iris and uvea, skin rash, inflammation of the joints, aphthous ulcers and clubbing of the fingers.

## Laboratory Findings
The laboratory findings in a patient with ulcerative colitis include anemia, low albumin, elevated ESR, elevated serum alkaline phosphatase, deranged LFTs and electrolyte abnormalities.

## Abdominal X Ray
Xray of the abdomen is not required for the diagnosis of ulcerative colitis. Xray may sometimes be one in case colitis is suspected. Xray is normal in mild to moderate disease and can show dilation and/or "thumb printing sign" in fulminant cases.

## CT
CT scan can b helpful in the diagnosis of severe ulcerative colitis and in differentiating ulcerative colitis from Crohn's disease. Initial changes in the mucosa may not be detected by a CT scan.

## MRI
MRI can b helpful in the diagnosis of severe ulcerative colitis and in differentiating ulcerative colitis from Crohn's disease. Initial changes in the mucosa may not be detected by a CT scan.

## Other Imaging Findings
Other imaging findings for ulcerative colitis can be seen by the help of barium enema. Barium enema may show micro ulcerations. barium enema must be avoided in severe cases as it can lead to the manifestation of toxic megacolon.

## Other Diagnostic Findings
Other diagnostic studies like upper endoscopy, colonoscopy, tissue biopsy and histological analysis can help with the diagnosis of ulcerative colitis.

# Treatment

## Medical Therapy
The first step in the management of an acute ulcerative colitis attack involves determining the anatomical extent of the disease endoscopically, and the severity of the disease, clinically. This classification is important to determine the necessity for topical (in distal disease) or systemic (in extensive disease) pharmacotherapy. Additionally, the severity of the disease may help determine the prognosis and the requirement for more aggressive intervention. Once the disease goes into remission, the goal of maintenance therapy is to prevent any subsequent acute exacerbations.

## Surgery
Surgical intervention (colectomy) in ulcerative colitis is reserved for management of severe or fulminant cases that are non-responsive to maximal medical therapy. Additionally, surgery is indicated for patients who develop complications such as colorectal carcinoma or toxic megacolon that does not resolve within 24 to 72 hours despite maximal medical therapy and intestinal decompression.

## Alternative Treatments
Limited evidence exists for the efficacy of alternative treatments for ulcerative colitis. Dietary modification, fish oil supplements, short chain fatty acid enema, herbal therapy, helminth therapy, probiotics, are the most common homepathic remedies used in ulcerative colitis. Data is lacking in regards to the efficacy of these therapies. Using these treatment modalities should not preclude physician-recommended, evidence-based interventions.

## Primary Prevention
The cause of ulcerative colitis is unknown, therefore primary preventive strategies are also unknown. Nonsteroidal anti-inflammatory drugs (NSAIDs) may make symptoms worse.

## Secondary Prevention
Due to the risk of colon cancer associated with ulcerative colitis. screening with colonoscopy is recommended for secondary prevention of ulcerative colitis. Adherence to maintenance therapy is recommended for secondary prevention of acute exacerbation of colitis.