Greetings from healthcaremagic.com .
I am Dr Sourav Chakraborty and I will be helping you with your query .
From your case history I do believe you are suffering from withdrawal. Generally when people who are heavily addicted tries to wean off such they do experience such systemic symptoms. My suggestion to you is not to give up on your trial to quit smoking
and do try to quit smoking at the earliest . Its not good for your health . Please visit a de addiction centre where they will chart out a plan for you so that you can quit smoking in a easier way.
Regarding your altered bowel habits I would suggest you to have isabgol husk two times a day and it will do wonders for you or please visit a physician for further evaluation .
Hope I have been able to help .