Constipation has too many variable contributors to be able to suggest a general frequency spectrum.
Constipation is a tough one, as this includes a diet involvement that also has to be considered..
Have you also looked at your diet? Certain food types are naturally congestive, such as wheat and corn flour products (Now that covers about 50% of manufactured foods)
One Electrotherapist has suggested to me that <RUN> on 5000hz (which is 5.00Khz) on the Rife Digital, has worked well for his clients. <RUN> at 5Khz for 2 hours with straps on the feet