Another hint...

...From Humaworm...

"Any type of digestion problems can be related to liver flukes. The liver produces bile which are the digestive enzymes of the body. The more flukes that are living in the liver - the less bile can be produced."

So, if perastaltic action is triggered by bile, and if the bile flow is blocked, or if the bile production is reduced, something is going to happen in the intestines!

Another piece of the puzzle falls into place.

f.