I suffer chronic constipation which has become especially bad since going on a low carb diet.

I took the following doses in my trial:
5HTP – 50mg 2/28/2011-3/4, 100mg 3/5-3/24, 150mg 3/25-
3/29, 200mg 3/30-4/3, 100mg 4/5-4/6, 400mg 4/7, 200mg 4/9, will continue with 200mg until run out
Bethenechol - 10mg 4/4, 20mg/25mg 4/5, 35mg 4/6, 50mg 4/8, 60mg 4/9

5HTP converts to serotonin which is released from gut cells upon pressure exertion in the gut; this should result in the release of acetylcholine (amongst otber things) which should promote contraction of muscles promoting peristalsis

Bethenechol – is an acetylcholine analog so taking bypasses the above process and directly stimulates the muscarinic receptors which again should result in peristalsis

Results: no increase in peristalsis whatsoever; still chronically constipation

Conclusion: I either have enough acetylcholine present or a problem with my acetylcholine receptors or other issue downstream of acetylcholine release such as inflammation or other additional issues needed to be addressed

Other items to consider:

casomorphins, gliadorphins - these act like opiods and are from the incomplete breakdown of gluten and casein; there is something called "opiod induced constipation"; I have long since removed gluten and will now eliminate casein

aloe vera - to combat inflammation in the gut; I found a study showing it reduces TNFalpha

B vitamins - after reviewing my food intake yesterday I realized I am not taking in enough B vitamins to even meet the RDA and this can result in constipation

vitamin A for G protein coupled receptors - this gets a little complicated but the acetylcholine receptor is a "G protein coupled receptor" and needs vitamin A and as it turns out, I am quite low it vitamin A