odd stools with constipation

About two months ago, I returned from a backpacking trip gone wrong and since I have been suffering with stomach pain and bloating off and on but normal stools. But about a week ago a strange new symptom immerged and I cannot figure it out so please help!!!

I felt extremely constipated no BM for three days, but then when I would strain to go, a very small amount of loose (almost diarrhea like) light colored stool would come out (yellowish/very pale)
This went on for a few days, very constipated but gassy and passing minute amount of this loose light colored stool (one time even greenish)

Finally I took ExLax and went A LOT and the stool was a normal color.
I felt un-constipated but had very bad gas pains for two days afterwards.
That was three days ago and I have not had a BM since (re-constipated,) but today I had the gas with tiny diarrhea light stool AGAIN and I am disturbed that the symptoms are back.

What can cause this? Constipated but with a little diarrhea of odd color at the same time? Help! Thanks.

[patient915]

Welcome to the gastroenterology community!  You are constipated and the reason you are having a little bit of diarrhea is because only the liquid can pass by the hard stool in your colon.  I would recommend seeing a doctor about this because you might have acquired something during your backpacking trip.  In the mean time you can try increasing your fiber intake and increasing how much water you drink to help with the constipation.