Ulcerative colitis:
ICD–10 | K51 |
ICD–9 | 556 |
OMIM | 191390 |
DiseasesDB | 13495 |
MedlinePlus | 000250 |
eMedicine | med/2336 |
Patient UK | Ulcerative colitis |
MeSH | D003093 |
Ulcerative colitis (ulcers in the colon) is an inflammatory bowel disease (IBD). Ulcerative colitis causes chronic inflammation and ulcers in the digestive tract and it affects the innermost lining of the large intestine, which includes the colon and rectum.
Ulcerative colitis has a lot in common with another form of IBD, known as Crohn’s disease. However, Crohn’s disease can affect the entire gastrointestinal tract while ulcerative colitis only attacks the large intestine. Also, ulcerative colitis can be treated by removing the entire large intestine by doing a total colectomy. Surgery for Crohn’s disease includes removing only the damaged areas of the intestine and reconnecting the non-damaged parts.
Causes of Ulcerative colitis:
The exact cause of ulcerative colitis is unknown. Researchers believe the following factors may play a role in causing ulcerative colitis:
- Overactive intestinal immune system
- Genes
- Environment
Overactive intestinal immune system. Scientists believe one cause of ulcerative colitis may be an abnormal immune reaction in the intestine. Normally, the immune system protects the body from infection by identifying and destroying bacteria, viruses, and other potentially harmful foreign substances. Researchers believe bacteria or viruses can mistakenly trigger the immune system to attack the inner lining of the large intestine. This immune system response causes the inflammation, leading to symptoms.
Genes. Ulcerative colitis sometimes runs in families. Research studies have shown that certain abnormal genes may appear in people with ulcerative colitis. However, researchers have not been able to show a clear link between the abnormal genes and ulcerative colitis.
Environment. Some studies suggest that certain things in the environment may increase the chance of a person getting ulcerative colitis, although the overall chance is low. Nonsteroidal anti-inflammatory drugs,1 antibiotics,1 and oral contraceptives2 may slightly increase the chance of developing ulcerative colitis. A high-fat diet may also slightly increase the chance of getting ulcerative colitis.3
Some people believe eating certain foods, stress, or emotional distress can cause ulcerative colitis. Emotional distress does not seem to cause ulcerative colitis. A few studies suggest that stress may increase a person’s chance of having a flare-up of ulcerative colitis. Also, some people may find that certain foods can trigger or worsen symptoms.
Pathophysiology
An increased amount of colonic sulfate-reducing bacteria has been observed in some patients with ulcerative colitis, resulting in higher concentrations of the toxic gas hydrogen sulfide. Human colonic mucosa is maintained by the colonic epithelial barrier and immune cells in the lamina propria. N-butyrate, a short-chain fatty acid, gets oxidized through the beta oxidation pathway into carbon dioxide and ketone bodies. It has been shown that N-butyrate helps supply nutrients to this epithelial barrier. Studies have proposed that hydrogen sulfide plays a role in impairing this beta oxidation pathway by interrupting the short chain acetyl CoA dehydrogenase, an enzyme within the pathway. Furthermore, it has been suggested that the protective benefit of smoking in ulcerative colitis is due to the hydrogen cyanide from cigarette smoke reacting with hydrogen sulfide to produce the nontoxic isothiocyanate, thereby inhibiting sulfides from interrupting the pathway. An unrelated study suggested that the sulphur contained in red meats and alcohol may lead to an increased risk of relapse for patients in remission.
Signs and Symptoms of Ulcerative colitis
The most common signs and symptoms of ulcerative colitis are diarrhea with blood or pus and abdominal discomfort. Other signs and symptoms include:
- An urgent need to have a bowel movement
- Fatigue (feeling tired)
- Nausea or loss of appetite
- Weight loss
- Fever
- Anemia—a condition in which the body has fewer red blood cells than normal
Less common symptoms include
- Joint pain or soreness
- Eye irritation
- Certain rashes
The symptoms a person experiences can vary depending on the severity of the inflammation and where it occurs in the intestine. When symptoms first appear,
- Most people with ulcerative colitis have mild to moderate symptoms
- About 10 percent of people can have severe symptoms, such as frequent, bloody bowel movements; fevers; and severe abdominal cramping.
Diagnosis:
The initial diagnostic workup for ulcerative colitis includes the following:
- A complete blood count is done to check for anemia.
- Stool culture, to rule out parasites and infectious causes.
- Erythrocyte sedimentation rate can be measured, with an elevated sedimentation rate indicating that an inflammatory process is present.
- C-reactive protein can be measured, with an elevated level being another indication of inflammation.
- X-ray. If you have severe symptoms, your doctor may use a standard X-ray of your abdominal area to rule out serious complications, such as a perforated colon.
- Colonoscopy. This exam allows your doctor to view your entire colon using a thin, flexible, lighted tube with an attached camera. During the procedure, your doctor can also take small samples of tissue (biopsy) for laboratory analysis. Sometimes a tissue sample can help confirm a diagnosis.
- Flexible sigmoidoscopy. Your doctor uses a slender, flexible, lighted tube to examine the sigmoid, the last portion of your colon. If your colon is severely inflamed, your doctor may perform this test instead of a full colonoscopy.
- CT scan. A CT scan of your abdomen or pelvis may be performed if your doctor suspects a complication from ulcerative colitis or inflammation of the small intestine. A CT scan may also reveal how much of the colon is inflamed.
Diagnostic Finding:
Signs | Crohn’s disease | Ulcerative colitis |
Terminal ileum involvement | Commonly | Seldom |
Colon involvement | Usually | Always |
Rectum involvement | Seldom | Usually |
Involvement around the anus | Common | Seldom |
Bile duct involvement | No increase in rate of primary sclerosing cholangitis | Higher rate |
Distribution of Disease | Patchy areas of inflammation (Skip lesions) | Continuous area of inflammation |
Endoscopy | Deep geographic and serpiginous (snake-like) ulcers | Continuous ulcer |
Depth of inflammation | May be transmural, deep into tissues | Shallow, mucosal |
Stenosis | Common | Seldom |
Granulomas on biopsy | May have non-necrotizing non-peri-intestinal crypt granulomas | Non-peri-intestinal crypt granulomas not seen |
Treatment and Drugs:
Ulcerative colitis treatment usually involves either drug therapy or surgery.
Anti-inflammatory drugs are often the first step in the treatment of inflammatory bowel disease. They include:
- Aminosalicylates. Sulfasalazine (Azulfidine) can be effective in reducing symptoms of ulcerative colitis, but it has a number of side effects, including digestive distress and headache. Certain 5-aminosalicylates, including mesalamine (Asacol, Lialda, Rowasa, Canasa, others), balsalazide (Colazal) and olsalazine (Dipentum) are available in both oral and enema or suppository forms.
- Corticosteroids. These drugs, which include prednisone and hydrocortisone, are generally reserved for moderate to severe ulcerative colitis that doesn’t respond to other treatments. Corticosteroids have numerous side effects, including a puffy face, excessive facial hair, night sweats, insomnia and hyperactivity. More-serious side effects include high blood pressure, diabetes, osteoporosis, bone fractures, cataracts, glaucoma and increased chance of infection. Their long term use can also lead to Cushing’s syndrome. They are not usually given long term.
Immune system suppressors
These drugs also reduce inflammation, but they do so by suppressing the immune system response that starts the process of inflammation.
- Azathioprine (Azasan, Imuran) and mercaptopurine (Purinethol, Purixam). These are the most widely used immunosuppressants for treatment of inflammatory bowel disease. Their use can effect the liver and pancreas. They can also lower the resistance as well as increase the risk of developing cancers such as lymphoma and skin cancers.
- Cyclosporine (Gengraf, Neoral, Sandimmune). This drug is normally reserved for people who haven’t responded well to other medications. Cyclosporine has the potential for serious side effects, such as kidney and liver damage, seizures, and fatal infections, and is not for long-term use.
- Infliximab (Remicade), adalimumab (Humira) and golimumab (Simponi). These drugs, called tumor necrosis factor (TNF)-alpha inhibitors, or “biologics,” work by neutralizing a protein produced by your immune system. These drugs also are associated with a small risk of developing certain cancers such as lymphoma and skin cancers.
- Vedolizumab (Entyvio). Works by blocking inflammatory cells from getting to the site of infection. It is also associated with a small risk of infection and cancer.
Other medications
- Antibiotics. People with ulcerative colitis who run fevers will likely take antibiotics to help prevent or control infection.
- Anti-diarrheal medications,
- Pain relievers. For mild pain,
- Iron supplements. If you have chronic intestinal bleeding, you may develop iron deficiency anemia and be given iron supplements.
Surgery
Surgery can often eliminate ulcerative colitis. But that usually means removing your entire colon and rectum (proctocolectomy). In most cases, this involves a procedure called ileoanal anastomosis that eliminates the need to wear a bag to collect stool. Your surgeon constructs a pouch from the end of your small intestine. The pouch is then attached directly to your anus, allowing you to expel waste relatively normally.
Cancer surveillance
You will need more-frequent screening for colon cancer because of your increased risk. If your disease involves more than your rectum, you will require surveillance colonoscopy every one to two years. You will need a surveillance colonoscopy beginning as soon as eight years after diagnosis if the majority of your colon is involved, or 10 years if only the left side of your colon is involved.
If in addition to ulcerative colitis you have a rare condition called primary sclerosing cholangitis, you will need to begin surveillance colonoscopy every one to two years after you have been diagnosed with ulcerative colitis.
[expand title=”References for Ulcerative Colitis:”]
–http://www.mayoclinic.org/diseases-conditions/ulcerative-colitis/basics/definition/con-20043763
–http://en.wikipedia.org/wiki/Ulcerative_colitis
–http://www.niddk.nih.gov/health-information/health-topics/digestive-diseases/ulcerative-colitis/Pages/facts.aspx#3
–http://www.nature.com/ajg/journal/v93/n1/full/ajg199821a.html#bib21
–http://link.springer.com/article/10.1023%2FA%3A1018851723920
–http://www.mayoclinic.org/diseases-conditions/ulcerative-colitis/basics/tests-diagnosis/con-20043763
–http://www.mayoclinic.org/diseases-conditions/ulcerative-colitis/basics/treatment/con-20043763
–https://www.youtube.com/watch?v=JMApMBY0CfQ
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