Kim,
You are going to find a lot of posts on this exact same subject...lots of us have lived through the horrors of hair loss to near balding post op, post colon, post pouch etc...some say that it is the anesthesia, others the vit/mineral loss, others the surgical shock etc...I say that it is all and more mixed together which means that there is no 'one size fits all' solution but there are a few tricks...After a horrendous run of a dzn surgeries that included tons of meds and sickness I lost a lot of my hair...my dermatologis finally put me on H&S shampoo...worked wonderfully...but you need to do a little 3-5min massage during the shampoo all over your scalp (head down if possible like leaning over the tub)...brings the blood flow to the scalp along with the massage that stimulates the hair folicles and the zinc in the H&S stimulates growth...in about 6 months I saw serious regrowth and by the end of the yr my hair was growing in thicker...a good multivitamin helps to and healthy diet and exercise do wonders too.
I can't give you any better advices than a good shorty haircut to give you some bounce and a lot of patience until it grows in.
Sharon