Abdominal Pain Improved After Cipro And Metronidazole, Neck And Joints Make Cracking Sound. Reason For Low Platelets?

Question: I have had 3 severe abdominal episodes that have been going on 2 months since Nov.19th 2011. The 2nd time was 3 days later.The 3rd time was 2 1/2 weeks from the 2nd time on Dec 12th when i went into the ER. I had a CT scan and blood work.My blood count looked good except for my platelet count was 53,000. In 3 test it has gone down each time from 53,000 down to 50,000 1 week later and down to 45,000 2 more weeks later. I am 43 yrs. old,6'1" 215 lbs. and have been healthy my whole life until now. I had a colonoscopy done a yr. ago only cuz' my father had an early detection of colon cancer that he is now clear of with no chemo after the surgery since it was caught early. I was told that a few relatives have had Diverticulitis before.My abdominal pain has improved after being put on Cipro and Metronidazole???? Occasionally just a lingering feeling in my stomach.My neck feels a bit achy and my joints are somewhat making a cracking sound. The pain in my stomach started around the belly button and a little to the left.I couldn't lay or stand or nothing to relieve the pain which seemed to last close to 24hrs. each episode. Each time it seemed to happen in the middle of the night. My platelets were at around 190,000 2 yrs. ago on a routine exam but since these episodes have been dipping and are at 45,000 currently. What can cause a low platelet count when the rest of the blood looks normal? Can the low platelets cause the body aches?I don't notice anything unusual when i go to the bathroom other than when i was put on the Cipro & Metro,that same night i had black tarry stool for 2 days then beck to normal by the 3rd or 4th day. After the meds were done in 10 days, the next night i had orange urine for 2 or 3 days than back to normal. Never any burning at all and only after the meds stopped.Also when i stopped the meds,that following night i would wake up with my heart racing. Can the meds have contributed to any of this?I had an ekg that looked good and wore a Holter to monitor my heart for 24 hrs. which also looked good. Not sure if stopping the meds or just stress and nerves of not knowing are now contributing to this! What other possibilities could there be for low platelets dropping with the rest of the blood count looking normal? Thanks D

Thanks for your help! Here's an update since your response. I had more blood test,this time for Hepatitis and a Viral Load which both came back NEGATIVE. I also went for a Bone-Marrow Biopsy that also came back NEGATIVE. I've had 4 blood test in 5 weeks and each time it has lowered. 53,000,50,000,45,000 and this last test was only a week later and remained at 45,000. My joints have become VERY achey over the past 2 weeks or so.My Whole body is sore. I haven't had the best sleep during all this and very stressed out! Can the stress and lack of sleep contribute at all to any of this? As mentioned as above, this all started with severe abdominal pain that came in 3 big episodes that led me to the ER the 3rd time in Dec. The Hematologist & The GI Doctor said i need to come in for a scope down my throat. Can stress really be the cause of a possible ULCER or is that just a myth? I have been under a lot of stress since the start of my symptoms and of course more stress trying to get answers for over 2 months.I've been healthy my whole life (43) til' now. I still wonder if it could be anything to do with food contamination at all? It all started very sudden a couple hrs. after going out to dinner and having steak & tomatoes as well! Could that have anything to do with lowering platelets and could it last this long? Like i mentioned the main thing now is the joint ache and what that cause may be? Thanks, XXXXXXX