For most abdominal CTs, intravenous (and sometimes oral) contrast is preferred because it improves detection and characterization of tumors, infections, inflammation and vascular injury; oral contrast can also help evaluate the bowel lumen. Non-contrast CT is typically used for suspected kidney stones, acute hemorrhage or when contrast is contraindicated (severe renal impairment or iodine allergy). Your doctor will choose based on the clinical question and kidney function.

CT scans with iodinated contrast can cause mild reactions such as nausea, vomiting, metallic taste, warmth, flushing, itching and hives. More serious but rare effects include allergic reactions (wheezing, shortness of breath, low blood pressure or anaphylaxis), contrast-induced kidney injury—especially with preexisting renal disease—extravasation at the injection site, delayed skin reactions and occasional thyroid dysfunction.

CT scans use ionizing radiation and children are more radiosensitive, so there is a small increased lifetime cancer risk—especially with repeated exams. When medically necessary, benefits usually outweigh risks. Radiology teams minimize exposure with pediatric protocols, dose adjustment, limited scan range, and alternative imaging (ultrasound or MRI) where appropriate. Discuss risks, benefits and options with your child’s clinician and radiologist before proceeding.

Arrive fasting for 4–6 hours (clear fluids usually allowed; hydrate well). Follow any oral-contrast drinking instructions given. Tell staff about allergies, kidney disease, diabetes, pregnancy, and all medications (you may need to pause metformin). Bring ID and prior imaging. You’ll get an IV for iodinated contrast; blood tests for kidney function may be required. Remove jewelry and follow check‑in instructions.

A CT abdomen typically shows the liver, gallbladder, spleen, pancreas, kidneys and adrenal glands; stomach, small intestine and colon; major blood vessels (aorta, inferior vena cava); lymph nodes, mesentery and peritoneum; the urinary bladder and pelvic organs (uterus, ovaries, prostate) when included; as well as bones (lumbar spine, pelvis) and surrounding fat and soft tissues.

Yes — you can usually drink clear water before an abdominal CT. Most centres allow clear fluids up to about two hours beforehand and encourage hydration, especially if IV contrast will be used. Avoid solid food for 4 to 6 hours and follow any instructions about prescribed oral contrast. Tell staff if you take metformin or have kidney disease for specific guidance.