I'm so sorry that you're still having issues. My wife had a sigmoid resection due to diverticulitis 13 months ago and is in worse shape than before. We've been to all the major hospitals in the Philadelphia area until one doctor cared enough. It turns out that she has a stricture at the anastomosis which is preventing stool from traveling normally to the rectum. She is also very low on B12. Next month, she will undergo a procedure to dialate the stricture. I can tell you then if its been successful. But at least she finally has some hope. Unfortunately, its getting worse worse over time. She can't even sit normally or drive anymore. A day out for her is to go to the doctor.
I hope you feel better soon.