I do get a feeling/sensation similar to the one you describe. Feels like a rock low down on the left in my belly and comes on about 4-5 hours after dinner in the evening.
When I get that it can do the same thing for a few days on a run, or maybe even do that for a couple of weeks. Then mine disappears and comes back another time for no obvious reason. It just feels like I really need to pass a lot of wind, but even if I pass a bit it doesn't go away.
Then for no reason I understand it goes and doesn't happen again for some time and it's been like that for at least 3 years. Same pattern.
I don't know what it is. It may be just sensitivity going on down there, to normal amounts of gas? Because I never pass a heck of a lot and not like everyone is supposed to normally. But I usually let some out when getting up in the morning. Then...not a toot all day long So for some reason I think a "normal" amount of gas somehow gets stored up at times and just irritates.