If you have acid exposure in the esophagus for even as little as a few weeks, you can develop inflammation of the lining. It can be very uncomfortable, even painful, and can leave the esophagus vulnerable to even more harmful erosion or scarring.Stomach acid can wear away the esophageal lining, causing sores or ulcers. (Esophageal ulcers are different than stomach ulcers, which are usually due to bacteria.) People with ulcers may spit up or vomit blood, or see it in stool. “It can be red or even darker, coffee-ground-like particulate.