Side effects are not always present in everyone. Others are more sensitive to side effects while they could be mild for others. If side effects ever become too much to handle, contact your doctor right away.
Common side effects of mesalamine may include:
stomach pain, nausea, gas;
fever, cold or flu symptoms;
rash; or
feeling tired.
Serious side effects of mesalamine may include:
severe stomach pain,
cramping, and
bloody diarrhea
these side effects may be accompanied by fever, headache and skin rash)
Signs to watch for:
Allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.