17 days is WAY TOO LONG!!! and dangerous to go without a stool!!!! I can see you have sought medical help. My foster son has a similar problem. He had to have surgery to enlarge the anal opening so that he could have stools. Still, he gets compacted, bloated, etc. He will expand from a 27" waist to 34" in a couple of hours. Two remedies....he is on Mineral Oil, Sorbitol, Simethicone (for the gas), and when constipation or very small stools are noticed, he is given a bottle of MAGNESIUM CITRATE. This has been a miracle worker with him! We also give him 32oz of prune juice per day, and this keeps him regular! Lots of fiber in his diet is very necessary and stay away from cheese, or other foods that tend to cause him to constipate.