What can be the cause of pain after treatment with the drug Pylera, a year has passed and there are still abdominal pains?

Here it is very difficult for you to determine what is happening and what is the cause. There is no information on exactly what drugs, apart from Pylera, were used during the treatment called eradication, which is designed to completely eliminate Helicobacter pylori from the gastric mucosa. As an adjunct during eradication and after its completion, for a long time, you need to take over-the-counter probiotics containing strains of bacteria, such as: Saccharomyces boulardi, Lactobacillus, or Bifodobacterium. The drug Pylera is a medicine that contains Bismuthum, Metronidazoleum, Tetracyclinum, and destroys the bacterial flora that is present in the intestines, and which is also responsible for the proper functioning of the digestive system. I suppose the cause may be just destroyed flora, but it's hard to say for sure. Abdominal pain can be caused by m.in.: stress, intestinal obstruction, liver or pancreas problems, irritable bowel syndrome, Crohn's disease, inflammation associated with appendix, gallbladder obstruction. However, you must turn to a doctor, because in absentia it is impossible to say what is happening.