Imodium (Loperamide) precautions. This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: stomach/abdominal pain without diarrhea, bowel obstruction (e.g., ileus, megacolon, abdominal distention). The rapidly dissolving tablets may contain aspartame or phenylalanine. If you have phenylketonuria (PKU) or any other condition that requires you to restrict your intake of aspartame or phenylalanine, consult your doctor or pharmacist regarding the safe use of this medicine.