Provisional good news:
When people lose their hair suddenly and rapidly, this is usally a "telogen effluvium." This forbidding name refers to a fairly common circumstance in which the body's rhythm is upset by a sudden "shock to the system": childbirth, high fever, rapid dieting, surgery, etc. This increases the percentage of hairs in the telogen, or resting, phase from 10% to 30% or so. About 2-3 months later, globs of hair fall out, especially up front. This never results in baldness and is reversible, as the body's rhythm reasserts itself.
In your case, the stress was clearly the GI bleed in October. The hair loss is this right on time.
It will gradually subside over a few months, with less and less hair coming out. Don't be afraid to comb or wash--the hairs that fall are already finished with their life span and aren't really attached anymore. (Look at the ends: you'll see a little white "club," what happens to the hair root when a hair is ready to fall out and be replaced.)
If your hair is still falling out in 2-3 months, check with your doctor, which you should anyway to be certain you aren't anemic. But the anemia's not the issue.
You may go bald some day, but not from this.
Good luck.
Dr. Rockoff
Dr. Rockoff
Does your head also itch? I think I may be experiencing the same thing, but my head itches like crazy and when I scratch even more hair comes out!