Hello! Thank you for the query. Constipation after antibiotics therapy is quite common condition. It is because antibiotics kill all good bacteria in our intestines. This bacteria are extremely important for proper bowels work. The protect us from bad bacteria infection. So most likely you are suffering from chronic intestines infection caused by antibiotics. As long as you wont rebuild the good bacteria and eradicate bad bacteria, constipation will be present. I suggest you to have stool culture test to choose proper antibiotic. Please discuss Rifaximine treatment with your doctor. You should also increase fiber rich products and mineral water intake. Physical activity greatly stimulates intestines. For fissure treatment you can: - wash your rectum after every stool - have sitz baths with Quercus Cortex - as your doctor about Nitroglycerine and Xylocaine gel Hope this will help. Regards.