It sounds very distressing to have persistent loose motions for 15 days despite treatment. Since you are still experiencing frequent diarrhea even after taking antibiotics like Taxim-O (a cephalosporin) and Rifagut 550 (rifaximin), it is important to see a gastroenterologist promptly for a thorough evaluation.

• Persistent diarrhea for more than two weeks may indicate an infection not fully treated by your current medications, or other causes such as inflammatory bowel disease or malabsorption.
• Avoid self-medicating further and maintain good hydration with oral rehydration solutions or fluids like buttermilk and coconut water.
• Keep a record of any additional symptoms like fever, blood in stool, abdominal pain, or weight loss, and share these with your doctor.
• Your doctor may recommend stool tests, blood tests, or imaging to identify the cause and guide appropriate treatment.
• If you develop severe dehydration, high fever, or blood in stools, seek emergency care immediately.

Please consult a gastroenterologist as soon as possible to get a proper diagnosis and tailored treatment plan.To narrow down potential causes, we will need some more information.I understand you've been dealing with loose motion for 15 days and the medications haven't fully resolved it. Could you please share your age and gender?