 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  too early may result in a return of the infection/ulcer. Tell your doctor if your condition lasts or gets worse.The side effects of Bismuth Subcit K-Metronidazole-Tetracycline Oral: Nausea, diarrhea, upset stomach, abdominal pain, changes in taste, headache, or dizziness may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly. Your tongue may turn dark in color while you are taking this medication. This is harmless, and the effect will disappear when you stop the medication. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor right away if you have any serious side effects, including: numbness/tingling of arms/legs, discolored teeth, mental/mood changes (such as confusion, anxiety, irritability, depression), difficult/painful swallowing, heartburn, fast/pounding heartbeat, ringing in the ears, frequent/painful urination, stiff/painful neck, signs of kidney problems (such as change in the amount of urine), signs of </s>