I'm sorry that you are so worried - I know how sometimes it seems that when it rains it pours. I highly doubt that the lump you are feeling has to do with the diarrhea or vomiting... you are most likely just overly anxious right now and are on "high alert" ...trust me, I have been there...and know that feeling - not fun!
Giardia sounds very possible...I would keep monitoring him and following the vet's instructions. Make sure he is drinking LOTS of water - with diarrhea/vomiting, they can get dehydrated so easily, and that can cause major problems. When our girls have had stomach issues in the past - we have used a syringe to give them Pepto Bismol, and have found it REALLY helps settle their tummies. Some on here might suggest you feed him rice and ground beef, as that might be easier on his tummy right now. I know you will get a ton of advice on here, just remember to breathe and tell yourself "this too shall pass". I'll be thinking of you and Murphy - and I hope everything is figured out really soon!
Giardia sounds very possible...I would keep monitoring him and following the vet's instructions. Make sure he is drinking LOTS of water - with diarrhea/vomiting, they can get dehydrated so easily, and that can cause major problems. When our girls have had stomach issues in the past - we have used a syringe to give them Pepto Bismol, and have found it REALLY helps settle their tummies. Some on here might suggest you feed him rice and ground beef, as that might be easier on his tummy right now. I know you will get a ton of advice on here, just remember to breathe and tell yourself "this too shall pass". I'll be thinking of you and Murphy - and I hope everything is figured out really soon!