As if the treatments aren't bad enough... Constipation is a common side effect of many of the things that happen after treatment ends. Strong pain killers cause constipation, the severe change in diet to liquids like Ensure etc. cause it, the lack of physical activity contributes to it, antibiotic therapy can contribute to it. All things that the months after radiation contain. Senecot worked for me, but it had rather..how shall I put it?...INTENSE, consequenses. I finally found that over the counter stool softeners from the drug store worked well. Also Ensure makes a formula that is high in fiber, and that helps, just make sure that you cut it 50/50 with water before you put it though the tube.