They can look at the gallbladder, pancreas, liver, & kidneys with ultrasound. The name of the test is Abdominal Ultrasound. I think the only prep for the test is to be fasting so food in the stomach doesn't get in the way of the ability to see the organs clearly. No IV's are required, no "gut cleanouts," just fasting, and they do rub some jelly-like stuff on the belly to help the ultrasound prope work better. This is a noninvasive and easy test. I've had a few of them...one of which was used to diagnose me with gallstones. I had the "keyhole" surgery but was kept overnight for observation post-surgery due to other issues (I'm complex medically). It took about a month for me to return to my normal activity level after the surgery, but I felt considerably better after the surgery - 15 years of nearly constant nausea disappeared with the removal of the gallbladder.
Chronic Lyme Disease, Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut issues (dysmotility, non-specific inflammation), UCTD ("Secondary Lupus-Like Syndrome"), Osteoporosis, chronic Lymphopenia, intermittant pancytopenia, chronic malabsorption/malnutrition, etc.; G-Tube; Currently TPN-dependent.
Meds: Zofran, Pulmicort, IV Ceftazidime, Heparin (to flush PICC line), Claritin, Domperidone, Colloidal Silver (used topically), probiotics, homeopathy.