Predicting when a remission may occur or when symptoms will return is not possible. Someone with Crohn's disease may need medical care for a long time, with regular doctor visits to monitor the condition. Most people are first treated with drugs containing mesalamine, a substance that helps control inflammation. Sulfasalazine is the most commonly used of these drugs. Possible side effects of mesalamine preparations include nausea, vomiting, heartburn, diarrhea, and headache.
Some patients take corticosteroids to control inflammation.
These drugs are the most effective for active Crohn's disease, but they can cause serious side effects, including greater susceptibility to infection. Drugs that suppress the immune system are also used to treat Crohn's disease. Most commonly prescribed are 6-mercaptopurine and a related drug, azathioprine. Immunosuppressive agents work by blocking the immune reaction that contributes to inflammation. These drugs may cause side effects like nausea, vomiting, and diarrhea and may lower a person's resistance to infection.