I don't have this issue, however, I had a big problem with undigested food. One thing I did that really helped was a dental clean-up. After having my root canals removed, it was amazing how my digestion improved. I eat pretty healthy, etc., but now I can relax a bit and eat something off the "plan" and not pay so dearly.
I went to Dr. Morales in Tijuana. I have no link to him or anything, just am impressed at how good he was and how reasonable his pricing was.