My personal feeling, and sense, is that feces cake up on the side of my colon somewhere, and sits there while normal ingestion bypasses it. Then, eventually, just before the
release, movements and gasses become extremely stinky. I hardly ever have diarrhea, cramps (except at release), abdominal pain, fever or nausea, or any other IBS symptoms. Naturally, I tend to gain some weight during this buildup.