Management of recurrent Crohn's disease.

After partial small bowel or colonic resection for Crohn's disease, recurrence frequently follows. Within half a year 60-73% of patients have endoscopic recurrence. This percentage increases substantially in as time passes. Symptoms will not always be present when endoscopic lesions are detected. The etiology of recurrent Crohn's disease is unknown. Some studies show that initial complications or extra-intestinal manifestations are more frequently seen in patients with a recurrence. The recurrent pattern of the lesions is also comparable to the pre-surgical state. The length of recurrent ileal inflammation after ileocolonic resection correlates with the pre-surgical extent of the disease. Some investigators have found electron-microscopic lesions in histologically unaffected resection margins demonstrating the presence of lesions. Luminal factors probably plays an important role as bypassing an anastomosis prevents an endoscopic recurrence. Some factors are considered to be important to increase the chance of a recurrence. A more aggressive disease may lead to earlier recurrence. Onset of disease at a younger age, a short pre-operative time, and localization, might play an important role. Smoking certainly influences the clinical, endoscopic and surgical recurrence. The number of daily cigarettes smoked and the duration of smoking, significantly increases the risk of recurrence. The type of surgery (kind of anastomosis, multiple anastomoses, length of resection) are not important. A longer macroscopic disease-free resection margin or presence of granuloma does not influence the recurrence rate. Also, the presence of microscopic disease at the margin is not important. Prevention of recurrent disease can be provided by administrating sulphasalazine, 5-aminosalicylic acid or metronidazole. For this reason, prophylactic medication after surgical resection seems appropriate.