Females are disproportionately affected by constipation, which is often aggravated during pregnancy.
Bowel function also changes during the luteal phase of the menstrual cycle.
Dr Michael Camilleri and colleagues from Minnesota compared the effects of acute administration of female sex steroids on gastric emptying in healthy postmenopausal subjects.
The research team also assessed the effects female sex steroids on small bowel transit and colonic transit in these subjects.
The team's secondary aim was to determine whether withdrawal of the hormones was associated with a change in transit.
The researchers randomized 49 postmenopausal females to 4 groups.
Subjects in Group 1 received for 7 days 400 mg day1 micronized progesterone, and those in Group 2 received 0.2 mg day1 oestradiol.
Group 3 had a combination of the 2 treatments, while subjects in Group 4 received placebo.
Treatment groups were balanced on age.
Participants underwent whole gut transit measurement by scintigraphy.
The researchers used a 99m-labeled technetium-egg meal and 111-labeled indium-charcoal via a delayed-release capsule.
Transit measurement was repeated after withdrawal of the study medications.
|Progesterone resulted in looser stool consistency|
|Neurogastroenterology & Motility|
The primary endpoints were ascending colon emptying half-life time, and colonic geometric center at 24 hours.
Secondary analysis variables were geometric center at 4 and 48 hours, gastric emptying half-life time and colonic filling at 6 hours.
The researchers found a significant overall effect of progesterone on colonic transit.
There was shorter ascending colon emptying half-life time and significantly greater colonic geometric center at 48 hours.
The team noted that no transit endpoints were altered by oestradiol or combined hormonal treatment relative to placebo.
Oestradiol and progesterone resulted in looser stool consistency.
Dr Camilleri's team concludes, “Withdrawal of the hormone supplement was not associated with significant alteration in transit.”
“Micronized progesterone does not retard colonic transit in postmenopausal females.”