Dextromethorphane HBr 20mg, Guaifenesin 400 mg -- "Signature Care DM Max Relief," a Safeway house brand of Mucinex. I took the recommended 20 mL dose one time per day. The first day, I experienced normal drowsiness, two days later on days 2 and 3 included minor stomach irritation as it entered my stomach. Day 4 was the last time I ever took this; the stomach pain was more pronounced, but did not go away. It has caused diarrhea, gas, and pain on the right side of the stomach organ and duodenum. Milk and bread do not hurt until later inside my intestines, always an eventual cramping sensation in my lower gut, but orange juice immediately burns my stomach. To accompany, my stomach organ twitches when food enters it (yes, the organ is twitching, not stomach as in "abdomen"), suggesting damage, that this drug may have over-thinned/stripped my mucous layer off my stomach/duodenum and exposed it to my stomach acid. I can only guess this has given me ulcers. I am not a doctor but I am very aware of my anatomy.
For the first week, I could not sleep on my right side after a meal, or else the food would contact the sore side and cause burning discomfort. Today, a week and a half since the 4th dose, I still cannot rotate in bed without having present pain in my stomach that "moves around" as though the pain had filled my stomach, every positional turn "awakening" the pain until it settles. There is a "not quite right" presence in my stomach and like I am over-full, but in reality I have barely eaten anything due to the pain, and I am losing weight very fast. I do not have an appetite and I cannot eat every day, while the first three days I did not eat at all. I am only just now feeling nausea with the inclusion of some very small amounts of food. Even water is hard on my stomach. The stomach twitching has stopped and it feels only a little bit less painful. It is in my best interest to assume the worst, ulcers, as they are the most serious and I do not have the funds for a checkup. I am aware of possible ignorance since ulcers have never been reported. I am very worried for my future quality of life.