We have analyzed the results of anti-inflammatory drug treatment of 100 consecutively treated patients with Crohn's disease. The disease affected the colon in 12 patients, small bowel in 36, and both colon and small intestine in 52. Thirty-two patients had had a prior resection of Crohn's disease. According to an adaptive design, patients were treated with sulfasalazine if able to take oral drugs; with steroids if unable to take, or unresponsive to, sulfasalazine; and with added azathioprine if unresponsive to sulfasalazine and steroids and unsuitable for surgery. Drug regimens included sulfasalazine alone in 39 patients, steroids alone in seven patients, both sulfasalazine and steroids in 43 patients, and added azathioprine in 11 patients. All patients completed at least 1 year, or were regarded as treatment failures after 3 months of drug treatment. We analyzed clinical and ra-diographic responses. Significant improvement occurred in all categories of patients: complete or partial clinical remission was observed in 79%, and complete or partial radiographic regression was observed in 55%; 30% of patients were not reexamined radiographically and the remainder showed no improvement. Our study suggests that properly selected anti-inflammatory drug therapy has definite benefits and is indicated for patients with Crohn's disease.