The meds will usually have a leaflet with them which tells you how you take them. This leaflet usually has a section about any precautions you should take including any other medications that you should avoid.
The immodium website says that it is unlikely to interact with other medications. I would be careful though since immodium is an anti -diarrhea medicine and could worsen any existing constipation. You may be better off using an antispasmodic such as busocpan