Dear An: Congrats on your son, yet it sounds like your own health has had some serious challenges. Let's start with the bleeding, OK?
If you had very regular periods before pregnancy, one would expect that underlying pattern to have returned by six months postpartum. There can be several causes for prolonged and heavy bleeding. The most common would be that you have not resumed regular ovulations yet.
As you may know, in a normal cycle, estrogen is produced all month. Estrogen is responsible for building up the lining of your uterus so you have something to shed each month. In a normal cycle, progesterone production increases following ovulation. Progesterone "stabilizes" the uterine lining in preparation for a possible implantation of a new pregnancy. If you are not pregnant that month the levels of estrogen and progesterone fall, triggering the release of the uterine lining—your period. So, if you do not ovulate, the estrogen build up of the lining continues, but without the usual ovulation associated progesterone. Thus, the hormone levels don't decline, and the lining stays up inside the uterus—your missed/late period. Alternatively the lining can begin to shed under its own weight producing prolonged bleeding.
Causes for not ovulating are multifold: thyroid problems, pituitary problems, ovarian cysts, physical stressors (eg sudden increases in exercise, crash dieting), emotional stressors (problems with boyfriends/girlfriends, finances), increased body weight, anorexia, rotating shifts at work, etc. Your hospitalization and rapid weight loss could certainly be perceived by the body as a stressor.
Another, less common reason for prolonged postpartum bleeds is infection. If a tiny fragment of pregnancy tissue is retained in the uterus it can set up a site for infection and inflammation. This makes the lining unstable and easier to bleed. Other signs of an infection may be present (eg tender uterus, fever)--but sometimes they will not.
PLEASE, please go back to your OB/GYN or clinic and ask them about the prolonged bleeding. After six months this needs to be evaluated.
In Concern,
Jane