Chemicals in both caffeinated and decaf coffee, like chlorogenic acids, may contribute to the digestive process and stimulation of the bowel, Singh says. Other underlying gastrointestinal issues may include irritable bowel syndrome (IBS), Crohn’s disease, or ulcerative colitis, which can all be exacerbated by the acidity in coffee, registered dietitian Nour Zibdeh, M.S., RDN, writes for mbg. “I would recommend people focus on adequate hydration, daily fiber consumption, and work with their physician to ensure there isn’t a causal reason for constipation,” Carrasco says. Opting for less acidic versions of coffee may also be beneficial for the gut.