Get emergency medical help if you have any of these signs of an allergic reaction to Imodium: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Stop using this medication and call your doctor at once if you have any of these serious side effects:
- stomach pain or bloating;
- ongoing or worsening diarrhea;
- diarrhea that is watery or bloody; or
- severe skin reaction - fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.
Less serious Imodium side effects may include:
- drowsiness, tired feeling;
- mild stomach pain; or
- mild skin rash or itching.
This is not a complete list of side effects and others may occur.