Too late, alas, but I’ve just remembered that liver paté has a terrible effect on the bowel bugle.
Incidentally my cycling buddy is a gastroenterologist and since I’ve been cycling with him my understanding of and respect for the human gastrointestinal tract has increased dramatically. Did you know, for example, that the rectum is well supplied with nerve endings that enable the brain to distinguish between liquid, solid and gaseous rectal contents? Usually…
Also the large bowel and the gut have no local pain receptors but lots of nerves that sense stretching, which is important in allowing us to detect blockages. My buddy says they sometimes cauterise the inside of the bowel and this is the reason why they inflate the bowel with CO2, as air would of course cause an explosion if the spark ignited any methane present. CO2 is also more readily absorbed through the wall of the bowel than air, leading to less discomfort.