Pepperoni PizzaDoes your IC flare when you’re having bowel discomfort? In the September 2008 article, Pepperoni Pizza: How the bowel Can Trigger Bladder Pain, researchers found that when the bowel becomes irritated, the bladder shows signs of irritation as well. IC and IBS are well-known related conditions though researchers are still struggling to figure out the connection and, as this study suggests, it may relate to shared nerves and/or neuroinflammation. One thing is for sure, both IC and IBS patients must avoid the nerve stimulating caffeine as well as more irritating foods such as pizza , both well known to trigger flares in the bladder and the bowel.