IBD.pdf

INFLAMMATORY BOWEL DISEASE There are two forms of inflammatory bowel disease (IBD): ulcerative colitis (UC), a mucosal inflammatory condition confined to the rectum and colon, and Crohn’s disease, a transmural inflammation of gastrointestinal (GI) mucosa that may occur in any part of the GI tract....

INFLAMMATORY BOWEL DISEASE There are two forms of inflammatory bowel disease (IBD): ulcerative colitis (UC), a mucosal inflammatory condition confined to the rectum and colon, and Crohn’s disease, a transmural inflammation of gastrointestinal (GI) mucosa that may occur in any part of the GI tract. The etiologies of both conditions are unknown, but they may have a common pathogenetic mechanism. Clinical Presentation of UC Clinical Presentation of CD  DIAGNOSIS The key diagnostic investigation in IBD is lower gastrointestinal tract endoscopy (sigmoidoscopy and colonoscopy), which allows direct visualisation of the large bowel and histopathological assessment from biopsies. Computed tomography (CT scan) and magnetic resonance imagery (MRI) are the best radiological methods for locating and defining fistulae and abscesses in active Crohn's disease. Although not diagnostic, active disease is suggested in patients with raised inflammatory markers that include erythrocyte sedimentation rate (ESR) and C- reactive protein (CRP) in addition to a low haemoglobin and raised platelet count. Vitamin B12 may be low in patients with chronic terminal ileal disease. Low red cell folate and serum albumin, magnesium, calcium, zinc and essential fatty acids also indicate chronic inflammation and malabsorption. Anti-Saccharomyces cerevisiae antibodies (ASCA) are more likely to be present in Crohn's disease. Serology can be used to exclude infection as a cause of diarrhoea. phARMAcOLOGIc TREATMENT The major types of drug therapy used in IBD are aminosalicylates, glucocorticoids, immunosuppressive agents, antimicrobials, agents to inhibit tumor necrosis factor-α (TNF-α) (anti–TNF-α antibodies), and leukocyte adhesion and migration (natalizumab). Severity of Ulcerative Colitis Treatment Algorithm for Crohn Disease SuRGIcAL TREATMENT In ulcerative colitis, surgical colectomy, temporary ileostomy and ileoanal pouch construction are all curative. These are the surgical interventions of choice, although proctocolectomy and permanent ileostomy also have a role. Curative surgery is not possible in Crohn's disease as recurrence elsewhere in the gut is inevitable. NON-phARMAcOLOGIc TREATMENT Protein–energy malnutrition and suboptimal weight is reported in up to 85% of patients with CD. The nutritional needs of the majority of patients can be adequately addressed with enteral supplementation. Probiotic formulas have been effective for inducing and maintaining remission in UC, but the data are not conclusive. For UC, colectomy may be indicated for patients with long-standing disease (>8 to 10 years), as a prophylactic measure against the development of CRC, and for patients with premalignant changes (severe dysplasia) on surveillance mucosal biopsies. The indications for surgery with Crohn disease are not as well established as they are for UC, and surgery is usually reserved for the complications of the disease. There is a high recurrence rate of Crohn disease after surgery. EVALuATION OF ThERApEuTIc OuTcOMES Patients receiving sulfasalazine should receive oral folic acid supplementation, as sulfasalazine inhibits folic acid absorption. The success of therapeutic regimens to treat IBDs can be measured by patient reported complaints, signs and symptoms, direct physician examination (including endoscopy), history and physical examination, selected laboratory tests, and quality of life measures. To create more objective measures, disease-rating scales or indices have been created. The Crohn Disease Activity Index is a commonly used scale, particularly for evaluation of patients during clinical trials. Standardized assessment tools have also been constructed for UC. Elements in these scales include (1) stool frequency; (2) presence of blood in the stool; (3) mucosal appearance (from endoscopy); and (4) physician’s global assessment based on physical examination, endoscopy, and laboratory data.