Metamucil twice daily with 6-8 glasses of water. This is a water soluble fiber source and is helpful in constipation and diarrhea. Your GI system needs it to function well.
Acidophilus caps or live yogurt to help rebalance the good bacteria in your gut. Once the balance is restored, then diarrhea, gas and bloating should resolve.
Calcium. This is better for diarrhea and you may well run short on this if you have constant diarrhea. This helps the bowel to absorb water back naturally, thus bulking up your stools.
Take a look at your diet too and cut things out which aggravate such as wheat, dairy, junk food and coffee, soda, alcohol.
Reduce stress levels if you can. This contributes to IBS via the mind/gut link.
Long term use of Immodium can cause more problems than it solves in the long run, so I would suggest that you try the Calcium supplements to help your diarrhea and ditch the Immodium.