Help my kitty's bum is bleeding

Hi everyone

I’m new to here. I’ve just rescued a kitten from the streets a couple of weeks ago. 5 days ago I took it to the vets to get the standard checkup. There was nothing wrong with it apart from a few lice (which has been ridden of) and there was a scab on one of his ear. Here are the details of my kitten:

2 months old
Weaned
Male

The vet gave a quick look and gave the standard deworming and antibacterial medicine for the fungus which explained the scab on his ear. As there were no actual problems with the kitten I was happy with that recommendation.

Since then my kitten has been displaying the following symptoms:

Diahorrea
Bleeding on its anus, renewed after each time going to the toilet then dries up after a minute or so
Not going to the toilet in the litter tray all the time. It used to go in the litter tray everytime.
Vomiting yellow liquid

I don’t know if its the medicine that is making it do this. I imagined that the deworming medicine has a laxative effect on the kitten, so if the medicine makes it want to go and it can’t go, it would cause bleeding in its intestines because its trying so hard?

From the forums I’ve read everyone seems to say go to the vets but since I’ve just been to the vets and these problems happen AFTER going to the vets should I go back to them or sit out the medicine course?

I tried calling the vets I went to but the assistant on the phone is just there to book appointments so she said for any specific questions like that I have to make an appointment. Obviously I’m a bit hesitant to do so if these symptoms are part of the medicine course and the fact that it costs so much money per visit. I’ve budgeted going to the vets once a month (saved up if I didn’t have to go that month), not twice a week!

Extra information: I’ve been feeding it dry kitten food with plenty of water that never runs out. I feed it twice a day and it finishes its food in the middle of the feeding times.
The vet said to give it wet food and because of where I live I don’t have easy access to wet kitten food so since it displayed the symptoms what I did was I quickly bought wet cat food and gave one meal but then the symptom got worse so I stopped.

I’ll just repeat my main question because I know I’ve been rambling a bit. So:

From the forums I’ve read everyone seems to say go to the vets but since I’ve just been to the vets and these problems happen AFTER going to the vets should I go back to them or sit out the medicine course?

Any extra advice please let me know. Thanks in advance!