Side effects of Imodium include constipation, dizziness, tiredness and drowsiness, states WebMD. Patients experiencing symptoms should discontinue use and contact a medical professional if symptoms persist or worsen, advises WebMD.
Rare, but serious side effects include severe stomach pain, bloating or loss of appetite, skin rash and nausea or vomiting require immediate medical attention, according to Drugs.com.
Patients are advised not to "double" missed doses of Immodium; symptoms of overdose include difficult urination, slowed breathing and deep sleep.
When used properly, Immodium effectively treats symptoms of sudden diarrhea, on-going diarrhea in persons with irritable bowel disease and reduces the amount of discharge in ileostomy patients.