Two things that will get the bowels moving quickly:
Magnesium -- you can use milk of magnesium, cheap magnesium oxide supplements and take several with water 3-4 times a day or you can try a bottle of magnesium citrate. Magnesium citrate works quickly but does cause cramping.
Vitamin C -- cheap ascorbic acid 2-3 grams every 30 minutes until you can go. I'd recommend pills, not the powder unless you have empty capsules.