Will a sonogram test reveal "stuck poop"?

Once the feces is that far down, the fluid taken orally will not reach it. Have you tried glycerine suppositories, they do help. You can always ask the Dr. to look that far down, but it sounds like constipation and not impaction. Not taking care of the problem will lead to impaction, so I'm really glad you're seeing a Dr for this. I have been in too many surgeries where the colon is perforated because patients did not take care of the issue. Perforation leads to massive infection and a colostomy (poop bag). Make sure to follow the drs advice to the letter to prevent bowel surgery. Even if you have a BM get that sonogram it could reveal the cause of your problem.