Bentyl is an anti-spasmodic taken for excessive motility. To get any benefit from it you should take it 45 minutes before any meal. If you are having frequent bowel movements after meals excessive motility/spasmodic pouch is more likely the culprit. If it's not coming right after you eat but consistently it's more likely pouchitis or Crohn's/untreated inflammation.
Sounds like you are a biologics candidate to me.