I Have An Ostomy Stoma From Colon Rectal Cancer, I

I have an ostomy stoma from colon rectal cancer, I took a Ducolax tablet and experienced severe cramps, most painful that I ever had. Now a full 24 hours later I am having cramps and a bright red discharge in the colostomy bag. I have used Ducolax before with no problems. The movement last night was watery with little solids. The amount of blood loss today is around 50 to 100 ML. No fever, but somewhat chilled and tired.
Any assistance will be appreciate.