I have a 3 1/2 year girl and a 5 month old boy BOTH had/have acid reflux. It was no fun. Before going to see your ped you can try gripe water it often works wonders. You can get it at Toys R Us it is safe, natural some doctors and lactation consultants will recommend it before zantac. I used the gripe water early with my 5 month and it helped considerably, he went on zantac at about 2 months though. I breastfed my 3 year old and I am breastfeeding my 5 month.
Some other possibly causes of the colic could be an allergy -milk (for example inability to digest the protein from the dairy I was eating- this happened with my 3 year old so I removed the dairy), a quick 'let-down' causing your baby to inhale a lot of air. My 5 month old is smart enough to pull away and let the flow slow down. If I only knew what was happening with my 3 yr old when she was younger. The stress I could have done without. ;-)
Best of luck figuring things out. My daughter was very colicky, but I got things straightened out and things with my 5 month are so much easier, experience I guess.
** helpful hint if you find yourself getting stressed during these crying episodes (more knowledge I wish I had) put on your iPod or headphones with music so you don't get so stressed out. Dance around with your baby and sing the songs Of course, make sure nothing is majorly wrong though. Besides if you relax, maybe your baby will relax sooner. You can always try and hope.