Hello and welcome to HCM,
Phantom pain is usually associated with removal of limb.
The pain associated with cholecystitis
pain) is localized to right upper quadrant which may radiate to right shoulder tip.
Pain in the lower back may not be associated with gall bladder problem.
A X-ray of the lower back needs to be done to know the cause of lower back pain.
Lumpy stools are seen in gastrointestinal tract abnormalities like malabsorption
You need to consult a gastroenterologist
for the symptom.
Thanks and take care
Dr Shailja P Wahal