An interesting article published in Dynamic Chiropractic. After being on call in the hospital so many nights and losing sleep, it was not uncommon for me to become irregular. This article is interesting and i am glad new light is being shed on this issue:
Melatonin and Irritable Bowel Syndrome
Melatonin is involved in the regulation of the sleep-wake cycle, circadian rhythms, and seasonal changes in the light-dark cycle. Commonly used to induce sleep, some (but not all) find that melatonin reduces jet lag. There is a high concentration of melatonin in the pineal gland, where it is manufactured. I was surprised to learn there are significant amounts of melatonin present in the gastrointestinal tract. Apparently, melatonin helps regulate gastrointestinal motility.
By Dr. Douglas Anderson, click here for full article