This is just my opinion to you, but the ultimate choice is yours, the more you know, the better for you to make your next decision.
After several discussion with you, unless you are in a life or death situation, I have a feeling that you are anxious to get your illness fixed by trying out all kinds of medication. Take it easy, you might actually hurting yourself by doing this.
Regarding the stomach and Colon Cleanse you mentioned, in my opinion, unless you are a heavy meat eater, taking a lot of drug and alcohol, eating a lot of fried or junk food, there's just no way your guts are dirty when you are a raw/wholefood foodist. You intestine should be clean without much toxins inside.
The reason for your sluggish bowel movement or constipation is because of your weakness in both "digestion fire" and "Lung Qi". There are two kinds of constipation: 1st kind is heat or toxin buildup on the intestinal wall which prevents you intestines to function normally; the 2nd kind is what TCM call it a weakness in the Qi in which your body has not enough power to push the food down. By you taking those cold bitter Chinese herb such as Corptis, the herb will weaken your own Qi when there's no heat to be cleared. As a result, since you are probably already in a Qi deficiency state, your sluggish bowel movement will actually become more worst after taking the bitter herb. Talk to another knowledge TCM herbalist and see what he/she says.
To distinguish whether the constipation is cause by toxin or Qi deficiency is very easy.
Constipation caused by toxin or heat:
Has a strong urgency to go to bathroom right away, but afterwards one still feels the waste hasn't been all emptied. Stools has a very dark color, sticky, and produce strong foul smell, and the diameter of the stool is large since the fecal matter have been compressed in the colon for a long time. In such case, cleaning and detox is required such as herbs, oxy-powerder, etc...
Constipation cause by weakness in Qi:
stools don't have a strong foul smell and non-sticky, and they usually come out as small size pebbles and you feel tired during or after such kind of bowel movement. Food eaten in a meal takes 2 or more days to come out in the stool. Try eating a meal with lots of carrot and see when it comes out. Carrot fibers are usually not digestible and you can see them in the stool. To help on this problem, eat peanut, walnut, peacan, saseme, or/and take other Qi tonic herbs such as astralagus or Korean gingsing (the red color kind, not American gingsing which has cool effect).
Sorry for all the descriptive words above.
If you indeed have a clean colon, after you tried Colon Cleanse product, I have a feeling that it will only produce watery stools with no foul smell instead of the plaque or dark color stuff. But you can prove me wrong on this and I will be happy to hear about it.