These instructions are general information. Your surgeon, anesthesiologist and hospital may give you different instructions based on your operation, medical conditions and medicines; their written plan takes priority. In the days before surgery, aim for regular meals with adequate protein and fluids unless you have been given a restriction. The day before surgery, choose familiar, easily digested foods and avoid alcohol or unusually heavy, fatty meals. Follow the hospital’s fasting times exactly and ask specifically about diabetes medicines, blood thinners, supplements and other regular medicines. Shower as instructed, remove jewelry and nail products if requested, and bring your medication list, scans and relevant reports.

Some colorectal operations require a low-residue diet, oral bowel preparation and sometimes prescribed antibiotics; others do not. Use FORTRANS only when it has been prescribed for your operation. If your written plan specifies three sachets, dissolve each sachet in one litre of water and drink the three litres at the exact times provided by the surgical team. Continue only permitted clear fluids and stop all oral intake at the time stated by the anesthesiology team. The preparation causes frequent watery bowel movements, so remain near a toilet. Contact the team if you cannot complete it, vomit repeatedly, feel faint or confused, have severe abdominal pain, or pass very little urine. Kidney or heart disease, fluid restrictions, diabetes, pregnancy, swallowing problems or a history of bowel obstruction require individualized instructions.

When you are well, a varied high-fibre diet can help bowel regularity: increase whole grains, vegetables, fruit, pulses, nuts and seeds gradually, and drink enough fluid. There is usually no need to avoid nuts, seeds or popcorn solely because of diverticular disease. During an acute painful flare, your clinician may advise a temporary clear-liquid or low-fibre diet, followed by gradual reintroduction of fibre as symptoms settle. Seek urgent assessment for worsening or persistent pain, fever, vomiting, abdominal swelling, inability to pass stool or gas, or significant rectal bleeding.

Food does not remove established gallstones, but regular balanced meals and gradual weight control may reduce symptoms and future risk. Avoid crash diets and rapid weight loss. If fatty or very large meals trigger pain, use smaller portions and choose lower-fat cooking methods while keeping adequate nutrition; individual triggers vary. Seek urgent care for severe or persistent upper-abdominal pain, fever or chills, yellow skin or eyes, dark urine, pale stools or repeated vomiting.

Follow the discharge plan for pain relief, wound care, eating, lifting, driving and return to work. Build activity gradually with frequent walking, adequate fluids and the recommended protein intake. Contact the team for increasing redness or drainage, fever, uncontrolled pain, persistent vomiting, progressive abdominal swelling, inability to pass urine, stool or gas, shortness of breath, chest pain, calf swelling, jaundice or any sudden deterioration.

Stopping smoking, limiting alcohol, maintaining activity and correcting poor nutrition before major surgery can reduce complications. Ask whether you would benefit from dietitian review, exercise or breathing training, iron treatment, diabetes optimization or other prehabilitation. Do not start supplements or stop prescribed medicines without advice.