Some people with UC may be sensitive to coffee because one of its main components, caffeine, is a stimulant, says Supriya Rao, MD, a gastroenterology, internal medicine, obesity medicine, and lifestyle medicine physician and a professor of gastroenterology at Tufts University in Massachusetts, where she treats people with IBD or other digestive health issues.
“It speeds up motility, which means things move through the gut more quickly,” says Dr. Rao. “That can be helpful for some people, but for people with UC, especially during a flare, that added urgency can make things worse.”
It’s also acidic, which typically isn’t helpful during a flare, when your intestines and stomach lining may be ultra-sensitive, Weekley says.
“Your stomach is already an acidic solution, so with coffee you’re dumping more acidity on top. During active inflammation with ulcerative colitis, it’s like you’re spreading more acidity on an open wound. It’s going to hurt,” she says. This is why you may feel symptoms like cramping, acid reflux and belly pain, too, especially if you’ve consumed coffee on an empty stomach, she says.
Beyond caffeine, a cup of coffee may contain other additives that may irritate the GI lining, including dairy and sweeteners, Rao says. “Many studies and anecdotal reports suggest that caffeine, dairy and artificial sweeteners can trigger symptoms in sensitive individuals,” she says.