My Daughter 45years Having Loose Motions For The Last Four

my daughter 45years having loose motions for the last four months.treated with antibiotics plus other supportive medications .but with no improvement.all lab tests are normal stool exam show fat contents only. she is having t2dm withOHA andhypothyroidism under control with drugs plus she is having multiple gall bladderstones.now she is put on tab. riagut400 threetimes dailyafter meal alongwith cap,bifilachp three times daily for 3..4 days and then two times daily.kindly suggest me this will be sufficient or need more investigations..like for celiac disease