Fiber

It has long been believed and promoted that all anyone with IBS needs to do is “eat more fiber.” Unfortunately, many physicians and dietitians are still advising this approach to their patients despite there being little evidence that more fiber in the diet benefits IBS symptoms or that too little fiber is a cause of IBS. And misguided friends and family will no doubt continue to offer up similar advice.

Generally speaking, vegans who eat a diet of mostly whole, minimally processed foods are already getting plenty of fiber. Foods rich in insoluble fiber include bran from whole-grain cereals and breads, cruciferous vegetables, and the skin of root vegetables (such as potatoes) and many kinds of fruit. Insoluble fiber can cause more harm than good in people with a hypersensitive gut because this type of fiber tends to cause fermentation, which can lead to bloating and gas, resulting in abdominal cramping and pain in people with IBS.