 <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]  doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.The precautions of Fiber Laxative (Methylcellulose) Oral: Before taking this bulk-forming laxative, tell your doctor or pharmacist if you are allergic it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this medication, tell your doctor or pharmacist your medical history, especially of: stomach/intestinal blockage, difficulty swallowing, appendicitis or symptoms of appendicitis (such as nausea/vomiting, sudden or unexplained stomach/abdominal pain), a sudden change in bowel habits that lasts for longer than 2 weeks, bleeding from the rectum. Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). Some products may contain sugar and/or aspartame. Caution is advised if you have diabetes, phenylketonuria (PKU), or any other condition that requires you to limit/avoid these substances in your diet. Ask your doctor or pharmacist about using </s>