If you're in your 40s or 50s and your digestion suddenly feels unrecognizable — bloating after meals that used to be fine, constipation one week and looseness the next, a waistband that's tighter even though nothing else changed — you're not imagining it, and you're not alone. In my practice, gut complaints are one of the most common things women bring up in the same breath as hot flashes and sleep problems. And now there's real research starting to explain why.