Post-abdominal surgery

Hello, I have a 2yo shihtzu terrier mix, he had abdominal surgery to remove a pile of sand that was in his stomach causing him to profusely vomit. He is 5 days post op. The vet gave him 4 medication, one for pain, one for nausea and GI motility and another one other one (not sure what for) but it has to be dissolved in water. Vet also put him on prescription GI soft food. Anyway, he is doing great up until last night he had several episodes of diarrhea. He is doing okay this morning though. Is this normal or something I should be concerned about. thanks in advance!

Hello!   It may not be a surprise to have episodes of diarhoea following on from all that, but it is important to let the vet know who is responsible for the case, because they will have an idea / judgement in their heads of at what point they would like such a case to be seen.  Best of luck.