Until now I have found only one empirical study which shows a correllation:
It reports traumatic sexual contact before age 17 as highly correlated with later hypochondriasis (28.6% of hypochondriacal patients versus 7.3% of nonhypochondriacal patients). But, nearly the same correlation was found also for physical violence (32.1% versus 7.3%) and major parental upheaval (28.6% versus 9.1%).
Thus, it seems to be not the "sexual", but the "traumatic" aspect of sexual abuse which is connected with later hypochondriasis. I have not found anything in this paper which relates consensual sexual experiences with later hypochondriasis.