TABLE I.

Correlation between hormonal status and IBS symptom expression

Status	Hormone levels	IBS and pain-related symptom expression	Reference
Late luteal phase (premenses)	rapid decline in estrogen and progesterone levels	exacerbation of bowel symptoms, increased bloating	17,19,21
Menstruation (menses)	lowest levels of estrogen and progesterone	exacerbation of bowel symptoms, increased abdominal pain/discomfort, lower rectal sensitivity threshold	18-20, 22,23
Dysmenorrhea	disturbances in hormonal interactions at different regulatory levels (lower progesterone level)	exacerbation of bowel symptoms	24
Oral contraceptives	estrogen and progestin administration	reduced abdominal symptoms at menses	30
Pregnancy	physiological hyperestrogenemia and hyperprogesteronemia	reduced pain sensitivity and alleviation of many chronic pain syndromes, exacerbation of constipation (prolonged gastrointestinal transit)	11,31,48
Menopause	decline in ovarian hormones	decrease in IBS incidence, high prevalence of constipation and somatic discomfort syndromes	15,34,35
Hormonal replacement therapy (HRT)	estrogen (and progesterone) supplementation	increased prevalence of IBS in postmenopausal women during HRT, prolongation of IBS symptoms to a later age	36
Ovariectomy	ovarian hormone deficiency	exacerbation or occurrence of gastrointestinal symptoms after gynecological surgery	38
Men with IBS	lower level of luteinizing hormone in middle-aged men elevated level of sex hormone-binding globulin in young men	generally more prevalent diarrhea (compared with women with IBS)	41,44
Transsexual women (male-to-female subjects)	estrogen/anti-androgen treatment	development of chronic pain including visceral pain	46