Suggest Remedy For Severe Lower Abdomen Cramping From Not Being Able To Pass Stool

I was diagnosed with anal stenosis (hemmeroidectomy 6 weeks ago) and I am having severe lower abdomen cramping from not being able to pass a stool. I have to strain and push very hard to get small worm like stools out but it very painful. My doctor tells me not to push because of my surgery. I have another surgery Tuesday 4/19 to do a dialation but this pain is extreme and I am not sure if this is dangerous. How can I absolve this pain?