since ur dr has seen the motions/stools and test have turned out normall,,,i would rely on it..
just keep an eye on it. if the stools are totly green,,,make it a concern to your dr.

stop carrots and avoid giving it as of now.some kids were sensitive to foods that high in beta carotene(carrots,sweet potatoes etc)..but being an infant age,,its early to conclude that...try after some 15-20days and see..offer the carrots, peeled(outerskin),boiled, mashed and strained ! strained so that hard fibrs in it are out and babies when started on solids to upto 8-9months,,needs strained pureed food as straining them thru the mesh, makes them easy to digest !!!
so offer accrdly..thats all i can say upto my reach.
carrot does not give frothy or green stool...if your baby is sensitive to carrots,,he might have got orange to yellow, or yellow to reddish/marronish type of colour,...and not green !

ABDEC,ferrium is baby vitamin(correct me if m wrong)..and it contains iron.which explains that he had bowels aftr a long gap.

why has your dr prescribed these extra supplements ? bowel movements have nothn to do wth supplemnts,,unless your child has shown ne lack of vitamin or iron or the supplemnts he has given contain high fibr,,whch is unlikely in case of infant/babiees below 2years...,

keep an eye on green colour..

about bm feeds,,make sure he takes it more often and if required, you can pump and store it,,and now that she is 6mnths, you cant expect her to pass bowels after all feeds,,the schedule might change dpnding on solids introduced,,so expect certain change or pattern or schedule change in that...
your 6months old should be on proper bm feeds, and not only 3times,,her total intake of formula or bm should be as below :
http://www.indiaparenting.com/boards/showmessage.cgi?messageid=6593&table_name=dis_feeding

http://www.indiaparenting.com/boards/showmessage.cgi?messageid=6452&table_name=dis_feeding

it will give you all idea hw to introduce foods and how much to give, bm and formula feeds, solids and wat all to plan for all the way upto 9months.
also go thru belw for the order in which you will offer vegies or fruits,,it will help you :

http://www.indiaparenting.com/boards/showmessage.cgi?messageid=7329&table_name=dis_feeding

good luck

Maybe my question was too short. this time let me elaborate. But Hetal.. thanks a lot for this quick response.

My baby was on BM for 6 months. absolutely nothing else and she had normal bowel movement, except for a case of UTI which we rectified with antibiotics, when she was 4.5 months. When she became 6 months, i started with solids for her with rice porridge first followed by mashed potato in about 2 weeks interval which she accepted too. her bowel movements were ordinary, about 2 times a day - once in the morning and again in the evening. In the meanwhile, I started with my work again. I continued with BM in the morning, afternoon (once during lunch break) and nights.

After this i wanted to try carrots with her. I did peel and boil carrots, but now i have doubts if i mashed it well, but she could swallow it. In this meantime, her doc suggested two general medicines for her (ABDEC and Ferium). 2 days later, she started hving bowel movements in about 5-10 mins after my BM feeds, which is given after a long gap - that is, when i return home to feed her in the afternoon and evening, she had bowel movements. Thereafter any more BMs in the night never triggered a bowel movement. And this motion was sometimes normal, sometimes loose, sometimes green, sometimes frothy. I am suspicious of the carrot (because that was the latest addition to her solids) and also my long-gapped-BM and also the ferrium.

I consulted with my doc. She did a Motion routine and said that was normal. she suggested 1 Econorm powder 2 times a day for 2 days and also vitazyme drops 2 times a day for 5 days. After this, there is some improvement. She doesn't poop after my BM on a regular basis. But she does that sometimes and her bower movements hv not returned to just 2 times a day. its about 5 times or so in small quantities - and its still sometimes frothy or green, but mostly normal.

Should I worry about this condition? Pls advise.

Big thanks again..