Burning sensation at the tip of penus

Hi, I am experiencing burning sensation at the tip of penus. It burns more after I urinate. I also have burning sensation in the anal area (seems to be coming from anus). I saw a urologist. He did urine test and did anal exam. He said no UTI. He said my prostate is little tender and diagnosed it as urithritis. He prescribed Doxycycline 100mg (2 tabs day). I have been taking it for 12 days. No improvement in the symptoms. Burning sensation in the anal area was not there before I started Doxycycline. Before going to the Urologist, I went to my primary care physician. She prescribed 2 tabs of Zythromycin 500mg and 1 tab of Cipro 500 mg. That did not help so I went to see Urologist. I have had digestive issues for the past 8 months. I took Pylera antibiotics back in September, 2008. Since then my bowl movements have been irrerugular (1, 2, 3 times a day ), irregular texture, color (green, brown). I had heart burn issues after taking Pylera. But heartburn is not there now. My endo doctor did endoscopy, colonoscopy, CT Scan. Nothing was found. He diagnosed it as IBS and hemmoroids (hemorrhoids). Sometimes when I wipe after bowl movement, I see blood. But I think this is when I eat spicy food,so I have been avoiding spicy food. After I started doxycycline, I have experienced burning sensation in my fee , especially when wearing shoes. This does not happen all the times.