In one sentence, describe what the following article is about:

You may find that no urine comes out of the catheter when you insert it. You can try rotating the catheter slowly to remove any blockage. You may also try pushing it one inch further into your penis or pull it back slightly.  You should also make sure the catheter opening is not blocked by the lubricant or mucus. You may need to remove it to determine this. If no urine comes out even after you rotate it, you can try coughing to encourage urine to flow. You may find it painful or uncomfortable to insert the catheter, especially when you are trying to push it past your prostate. You may need to put more lubricant on the catheter to make it easier to insert. Take a deep breath in and try to relax as you push the catheter in to make it easier to insert. If it is still difficult, do not force it. You may want to wait an hour and try again, focusing on staying relaxed and calm as you insert it in. If you cannot urinate even with the assistance of the catheter, or you are experiencing other urination issues, like blood or mucus in your urine, you should see your doctor. You should also see your doctor if you develop stomach cramps, your urine appears cloudy, smelly, or discolored, or you feel feverish. You may have a urinary issue that needs to be addressed before you can try using the catheter again. You can still have sex if you need to use a catheter. If you plan to engage in sexual intercourse, it's a good idea to catheterize beforehand to remove any urine that is present in your bladder. Always remove the catheter before having intercourse. If the urine is strong or offensive, don't have sex until you can get treatment for a possible infection.

Summary:
Rotate the catheter if no urine comes out. Apply more lubricant if you find it difficult to insert the catheter. See a doctor if you cannot seem to urinate or you have other urination issues. Catheterize before sex if necessary.