What Causes Vibrating Sensation On Lower Abdomen?

Question: Hi. I have some vibrating sensation on my lower abdomen over the past few months but I couldn't pinpoint the exact location, now it's from my lower left side I think. I have no pain at all. My everyday life is carried on normally. The sensation is coming 24 hours/7 days. Recently I went for vacation and after coming back from vacation I never felt the sensation for 2 days but after that the feeling came back again. I suspected it is because that sometimes I have some constipation problem but I had taken laxatives prescribed by doctor still the condition persists. My doctor prescribed me bacterial infection medicine also but after taking it I still feel the same. Then I decided to start observing my stool changes. these two days the same problem I realized is there, I found out that the first stool comes out is hard and has some white streak on it but the subsequent stools are normal, is this indicate any clinical problem? I suspected it could be due to some vitamin deficiency also like vit.b12 so I took multivitamin tablet yesterday and afterwards the vibrating sensation had became so strong for all day till I woke up the next day the sensation had became subsided a bit just like how I feel it everyday.By the way I've gone for ultrasound check up, doppler ultrasound and also mri, everything is normal. My doctor told me to go for colonoscopy as the last resort but I don't wish to. I just wanna get rid of this feeling because whenever I sit down or lying down during sleeping time I can feel it so obviously. Sometimes it would disturb me from falling asleep. :(

since 3 weeks ago I started drinking 3 litres of water everyday, went for jogging a few times in a week and added more fibres into my diet, still the sensation persisting but I'm not too sure whether it has subsided a little bit. Now I would pass my stool normally everyday or two days once but still the sensation is there. There was once after I took multivitamin the sensation became so exaggerated on that particular day. why is it so? Sometimes I would shake my leg to distract myself from the sensation and the sensation would subside but after few seconds it returned back again. I don't feel stress at all. I never had this symptom in the past 20 years. I'm a Malaysian who's studying abroad now in XXXXXXX Tamil Nadu, India. I hope you're able to help me. Thank you so much!