Sorry to hear but I am starting to believe that we never get rid of pin worms.
The ulcer is probably caused by ascaria. That is the issue I had. I started taking HCL and digestive enzymes with each meal and the ulcer healed. You can buy HCL with simethicone.
MY opinion. The parasites eat a hole in our duodenum because that is the usual place they sit waiting for you to feed them. If you don't keep feeding them then they eat you. So feed them some panacur powerpak horse paste in between meals and see if they like that. I have found that when using the panacur it is best to fast if you can. The ascaria are hiding in the food or the food is absorbing and diluting the panacur. I can't explain it but I know it works to fast.