Why does wife say she has to wait 6wks to have sex after a hysterectomy?

Opening of wound. Dr. Vanko's answer may sound dramatic, but vaginal penetration before the vagina has fully healed can cause the incision at the top of the vagina to open and intestine to slip into the vagina. I saw this in our emergency room last week.
Hyst healing. You don't want her vagina to rip open and her bowel to come out her vagina. Wait the six weeks!