Aminosalicylates for Inflammatory Bowel Disease


Generic NameBrand Name
balsalazideColazal, Giazo
mesalamineAsacol, Canasa, Rowasa

How It Works

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

Why It Is Used

Aminosalicylates have been used to treat IBD for more than 30 years. They usually are the first medicines used to treat ulcerative colitis. But experts don't agree on the use of these medicines for Crohn's disease.

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

  • Sometimes oral aminosalicylates are used to treat Crohn's disease. For example, they may be used to treat active disease (a flare-up) that affects the colon (colitis).

How Well It Works

The use of these medicines depends on the disease (ulcerative colitis or Crohn's), the type of medicine (oral or topical), and whether the disease is active or in remission.

Ulcerative colitis

Aminosalicylates work for mild to moderate ulcerative colitis.

Treatment for mild to moderate ulcerative colitis often begins with sulfasalazine. Sulfasalazine works 40% to 80% of the time to make ulcerative colitis symptoms better or keep them from coming back.footnote 1 But it cannot be used by people who are allergic to or cannot tolerate sulfa drugs.

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.

Mesalamine enemas are effective in treating symptoms of mild to moderate distal (left-sided) ulcerative colitis and in maintaining remission.footnote 1 Mesalamine suppositories are preferred for people who have proctitis. 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.footnote 1

These medicines can be used to maintain remission in ulcerative colitis.

Crohn's disease

Experts don't agree on the use of aminosalicylates for Crohn's disease. It's not clear how well they work to treat the disease.footnote 2 Sometimes these medicines are used to treat active Crohn's disease (a flare-up) that affects the colon (colitis). Your doctor may also recommend aminosalicylates at other times.

Side Effects

All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

Here are some important things to think about:

  • Usually the benefits of the medicine are more important than any minor side effects.
  • Side effects may go away after you take the medicine for a while.
  • If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

Call 911 or other emergency services right away if you have:

  • Trouble breathing.
  • Swelling of your face, lips, tongue, or throat.


Call your doctor right away if you have:

  • Hives.
  • Aching joints.
  • A headache that won't go away.
  • A fever.
  • Itching or a rash.
  • Skin sensitivity to sunlight.


Call your doctor right away if you have:

  • Hives.
  • Severe belly pain or cramps.
  • Bloody diarrhea.
  • Itching or a rash.
  • A severe headache.

All aminosalicylates

Common side effects of aminosalicylates include:

  • Mild stomach pain or cramps, nausea, or loss of appetite.
  • Diarrhea.
  • Dizziness.
  • Mild headache.

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

What To Think About

Sulfasalazine can make your skin more sensitive to the sun.

  • Stay out of the sun, if possible.
  • Wear long pants, long-sleeved shirts, and hats, if possible.
  • Use sunscreen with an SPF that your doctor recommends.

Taking medicine

Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.

There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.

Advice for women

If you are pregnant, breast-feeding, or planning to get pregnant, do not use any medicines unless your doctor tells you to. Some medicines can harm your baby. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. And make sure that all your doctors know that you are pregnant, breast-feeding, or planning to get pregnant.


Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

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. Ford AC, et al. (2011). Efficacy of 5-aminosalicylates in Crohn's disease: Systematic review and meta-analysis. American Journal of Gastroenterology, 106(4): 617–629. DOI: 10.1038/ajg.2011.71. Accessed November 5, 2014.


ByHealthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer Arvydas D. Vanagunas, MD - Gastroenterology

Current as ofNovember 14, 2014