Poop help!

So my 9 month old has been super grumpy the past 2 days, last night he hardly slept and has only had 4oz of milk in the last 20 hours. He’s been crying his eyes out like he’s in pain, has had a temp of 38.7c/101fh. He’s had a bit of an upset tummy for the past couple of days but this morning did this. Any ideas what it could be? I don’t want to ring the doctors unless I 100% have to because they’ll immediately jump to Covid because of his high temp!