Hi and welcome to HCM.
This is rarely caused by gallbaldder surgery unless there was baldder or ureter injury
. but it would be reported. it is more possible uroinfection which is common in people that underwent any surgical procedure since their immune system is weakened few weeks after surgery. she should treat it by taking lot of fluids and antibiotic if necessary. diarrheas may be experienced after gallbaldder surgery but it shouldnt last for more than 2-3 months. if there is no improvement she may need gastroenterologist work up to rule out some bowel disorders.
Thanks for the query. Regards