Carafate is an anti-ulcer medication. Carafate is not greatly absorbed into the body through the digestive tract. It works mainly in the lining of the stomach by adhering to ulcer sites and protecting them from acids, enzymes, and bile salts. Carafate is used to treat an active duodenal ulcer. Sucralfate can heal an active ulcer, but it will not prevent future ulcers from occurring. Common side effects of Carafate include constipation, diarrhea, nausea, vomiting, upset stomach, stomach pain, indigestion, flatulence, dry mouth, itching or skin rash, sleep problems (insomnia), dizziness, drowsiness, spinning sensation, headache, or back pain.