Medical treatment: does it influence the natural course of inflammatory bowel disease?

It is difficult to predict the clinical course of inflammatory bowel disease (IBD). Moderately sick Crohn's disease (CD) patients and patients with distal ulcerative colitis (UC) may get better even without medical or surgical treatment. Once better, they may continue in remission even without treatment. If they are not treated, there are several factors that predict whether they will maintain remission. Most patients will probably alternate between remission and relapse, with 10% having a relapse-free course after 10 years, and only 1% having a continuously active course. Frequent relapses initially are associated with active disease later on, but the disease activity course is independent of the response to the initial medical treatment. There is a cumulative frequency of operation of 50-80% and of reoperation of 33% in CD, which suggests that CD has a more serious course than UC. In UC, the overall probability of surgery is 33% for pancolitis and 10% for proctitis within 5 years of diagnosis, and the majority of patients are operated on within the first few years. Maintenance treatment with sulphasalazine (SASP) and 5-aminosalicylic acid (5-ASA) in UC has reduced relapse rates to about half over a 1-year follow-up period. The use of 5-ASA for maintenance of CD has been shown to result in only a modest therapeutic gain, while azathioprine and 6-mercaptopurine (6-MP) improve the relapse frequency for at least 3 years whilst on treatment. Changes in disease distribution in UC are part of the natural course of the disease, which should have implications for medical treatment strategies, and affects the risk of colectomy and colonic cancer. Certain enviromental factors are thought to determine disease activity and disease outcome in UC and CD. Patient compliance with prescribed medication and clinical check-ups must be considered another non-specific variable affecting the clinical outcome. IBD frequently requires potent medication with side effects that limit patients' acceptance. Such patients often resort to medicinal herbs, acupuncture, and homeopathy, which may alter the expected course.