Inflammatory bowel disease (IBD) comprises ulcerative colitis and Crohn’s disease, which are inflammatory disorders that have a chronic, relapsing and remitting course, usually extending over years. Ulcerative colitis involves mainly the colon, and Crohn’s disease can involve any part of the gastrointestinal tract but usually small intestine. Both diseases mainly start either in young adults or in the seventh decade of life.
Causes of IBD
The cause of IBD is still not certain. Both genetic and environmental factors are implicated. There is up to 20-fold higher risk of contracting IBD in first-degree relatives of those having IBD; 5% higher risk in a child if a parent is affected; high concordance between identical twins. The genes implicated are IBD1, CARD15, and other susceptibility genes located on chromosomes 12, 6 and 14.
Ulcerative colitis is more common in non-smokers and ex-smokers than in those actively smoking. This should not be construed as implying that smoking would necessarily lead to an improvement of the symptoms. Crohn’s disease is more common in smokers. IBD is also associated with low-fiber, high refined sugar diet. Also, high intake of animal protein from meat and fish carries an increased risk of IBD. Interestingly, appendicectomy (removal of appendix) protects against ulcerative colitis.
Signs and Symptoms of IBD
The first attack is usually the most severe, followed by relapses and remissions. Very few patients have a chronic, unremitting course. Infection, emotional stress, gastroenteritis, antibiotics or a type of analgesic therapy (NSAIDs) may provoke a relapse.
The clinical features depend on the site and activity of the disease. There could be rectal bleeding and mucus discharge, or bloody diarrhea with mucus, sometimes accompanied by tenesmus. Some patients could also have constipation and passing of pellety stools. Abdominal pain, fever, anorexia, malaise and weight loss can be present.
There is abdominal pain, often associated with diarrhea which is watery and does not contain blood or mucus. Weight loss is present in most patients, either due to avoidance of food, as eating can provoke pain, or due to malabsorption.
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Abdominal mass and tenderness, and anemia may be the other features. If it involves colon, the symptoms are identical to those of ulcerative colitis. Presence of anal fistulas or abscesses goes more in favour of Crohn’s disease.
Complications of IBD
Some of the complications of IBD are intestinal ones like toxic megacolon, perforation of small intestine or colon, life-threatening acute haemorrhage, perianal disease like fistulas, and increased risk of colon cancer after 8 years of the disease. Extraintestinal complications of IBD are many, for example, mouth ulcers, joint pains, stones in gall bladder, fatty liver, liver abscess, ankylosing spondylitis, erythema nodosum, pyoderma gangrenosum, and metabolic bone disease.
Diagnosis of IBD
Blood tests reveal presence of anemia and raised ESR. Blood and stool cultures can be done to rule out infection. Endoscopy (sigmoidoscopy and colonoscopy) can show areas of inflammation with characteristic lesions. X-rays and MRI also are useful to diagnose IBD.
Treatment of IBD
The principles of drug treatment are similar for ulcerative colitis and Crohn’s disease. Active disease is managed by steroid therapy. Prednisolone (30-40 mg/day orally) is given for 2 weeks and then reduced slowly over 8 weeks. Sometimes steroids can also be given intravenously or in the form of suppositories and enemas.
In those relapsing frequently after courses of steroids can be given immunosuppressants like azathioprine, but they start having effect only after 6 to 12 weeks, so steroids should be given in the meantime. Antidiarrheal agents are useful, but should be avoided in severe acute disease. Maintenance of remission is with aminosalicylates like 5-aminosalicylic acid (5-ASA) and its derivatives sulfasalazine, mesalamine, balsalazide and olsalazine.
Sometimes aminosalicylates can be tried as first-line agents. Other drugs that have a place in treatment are immunomodulators like infliximab, natalizumab, adalimumab and certilozumab. Therapy with methotrexate, cyclosporine, nicotine patch, butyrate enema, heparin and thalidomide is in the experimental stages.
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