Aminosalicylates for inflammatory bowel disease


Generic Name Brand Name
balsalazide disodium Colazal
mesalamine Asacol, Canasa, Lialda, Rowasa
olsalazine sodium Dipentum
sulfasalazine Azulfidine

How It Works

These medicines may relieve symptoms and inflammation in the intestines and help IBD go into remission (a period without symptoms). They also may help prevent the disease from becoming active again.

Why It Is Used

Aminosalicylates usually are the first medicines used to treat inflammatory bowel disease (IBD). These medicines have been used to treat IBD for more than 30 years.

Ulcerative colitis

  • Oral and topical aminosalicylates are used to treat mild to moderate ulcerative colitis. They also are used to help keep the disease in remission.
  • Oral aminosalicylates are used to treat mild to moderate extensive disease (pancolitis).
  • Mesalamine (Canasa, Rowasa) is placed in the rectum as a retention enema or suppository. Enemas are useful if the disease affects only the lower third of the large intestine. Suppositories may be used if the disease affects only the lower rectum (proctitis).

Crohn's disease

How Well It Works

These medicines are effective for mild to moderate ulcerative colitis and mild Crohn's disease. Their use depends on the type of medicine (oral or topical) and whether it treats disease that is active or in remission.

Ulcerative colitis

  • Treatment for mild to moderate ulcerative colitis often begins with sulfasalazine. But it cannot be used by people who are allergic to or cannot tolerate sulfa drugs.
  • Sulfasalazine works 40% to 80% of the time to make ulcerative colitis symptoms better or keep them from coming back.1
  • Mesalamine, olsalazine, and balsalazide do not contain sulfa, so they may be used to treat mild to moderate ulcerative colitis if you cannot take sulfasalazine. About 80% of people who can't take sulfasalazine can use mesalamine without problems.1
  • Mesalamine is becoming the medicine that doctors use first to treat mild to moderate ulcerative colitis.
  • Mesalamine enemas are effective in treating symptoms of mild to moderate distal (left-sided) ulcerative colitis and in maintaining remission.1
  • The combination of a mesalamine pill (oral) and a mesalamine enema, foam, or suppository (topical) works better to treat left-sided colitis than either oral or topical mesalamine by itself.1
  • Topical mesalamine enemas and suppositories work more quickly, have fewer side effects, and do not need to be used as often as oral mesalamine for disease in the rectum.1 They are most effective when used while you are sleeping.
  • Mesalamine suppositories are preferred for people who have proctitis.
  • Sulfasalazine, mesalamine, balsalazide, and olsalazine can be used to maintain remission in ulcerative colitis.

Crohn's disease

  • Sulfasalazine may be used for mild Crohn's disease of the colon. Some people are allergic to sulfa drugs and cannot take sulfasalazine.
  • Mesalamine has been shown to stop the symptoms of Crohn's disease in some people. Studies show that about 45% to 55% of people treated with mesalamine go into remission (a period without symptoms).2
  • Aminosalicylates do not seem to keep symptoms from coming back when a person is in remission caused by drugs (like corticosteroids). But aminosalicylates sometimes keep symptoms from coming back in people who have had surgery.3

Side Effects


Side effects may include headache, nausea, loss of appetite, vomiting, rash, fever, and decreased white blood cell count. Sulfasalazine also can temporarily reduce sperm production in men while they are taking the medicine.

Most side effects can be relieved by taking smaller doses with food at intervals throughout the day (instead of a single large dose), using coated tablets, or lowering the dose.

Folic acid supplements and regular blood tests to check the white blood cell count may be needed while taking sulfasalazine.


Side effects may include stomach pain and cramps, diarrhea, gas, nausea, headache, and dizziness. The medicine may cause kidney problems if taken in high doses or for a long time.


Diarrhea is the most common side effect. Uncommon side effects may include headache, rash, fatigue, hair loss, inflammation of the pancreas (pancreatitis), or inflammation of the tissue surrounding the heart (pericarditis).


The most common side effects are headaches and abdominal pain. Other possible side effects are nausea, diarrhea, and vomiting.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Aminosalicylates are used for long-term maintenance in ulcerative colitis. They are not as effective for long-term treatment of Crohn's disease.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.



  1. Friedman S, Lichtenstein GR (2006). Ulcerative colitis. In MM Wolfe et al., eds., Therapy of Digestive Disorders, 2nd ed., pp. 803–817. Philadelphia: Saunders Elsevier.
  2. Friedman S, Lichtenstein GR (2006). Crohn's disease. In MM Wolfe et al., eds., Therapy of Digestive Disorders, 2nd ed., pp. 785–801. Philadelphia: Saunders Elsevier.
  3. Akobeng AK, Gardener E (2005). Oral 5-aminosalicylic acid for maintenance of medically-induced remission in Crohn's disease. Cochrane Database of Systematic Reviews (1). Oxford: Update Software.

Last Updated: October 9, 2008

related physicians

related services

Bon Secours International| Sisters of Bon Secours USA| Bon Secours Health System

This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Privacy Policy. How this information was developed to help you make better health decisions.

© 1995-2010 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.