I thought Issybird might get this one.

Not Pynchon. Sadly this author died unaware of the critical and commercial success this novel would have. For those other than Issybird one more passage:

But since the attempted arrest and the accident, he had been bloating for almost no reason at all, his pyloric valve snapping shut indiscriminately and filling his stomach with trapped gas, gas which had character and being and resented its confinement. He wondered whether his pyloric valve might be trying, Cassandralike, to tell him something.