I came accross this really eye opening info while reading on potty training my toddler who happens to prefer squatting.... It Points out that Crohn's and other IBDs are only present in Western nations and diet has not proven to be the cause. Instead they present theory and very convincing evidence that sitting toilets through mis-aligning the colon and producing stress on the pelvic floor, produce a whole host of pelvic intestinal, and bowel disease.

Check it out, the whole page is about effects of toilet position: Health Benefits of the Natural Squatting Position

Also, I agree with the above poster who suggested indicas. Sativas can be stimulating, including to the intestines.

best of luck