Effectiveness and Cost-effectiveness of Sacral Neuromodulation in Patients With Idiopathic Slow-transit Constipation

"SNM starts with a screening phase. In this phase a tined lead is inserted into the third sacral foramen and attached to an external stimulator, after which the patient enters a four-week stimulation test period. If the screening phase is successful (defecation frequency (DF) ≥3 a week), the external stimulator is changed for a pacemaker that is implanted in the buttocks. If the screening phase is unsuccessful (DF \<3 a week), the lead is explanted.~Patients in the intervention group are asked to limit the use of additional conservative treatments for constipation (such as laxatives and colonic irrigation) to what is necessary to relieve (the most severe) complaints. What is necessary to relieve complaints is determined by the patient."

The control group will receive the best and least invasive alternative treatment, which is personalized conservative treatment (PCT). PCT includes, a combination of laxative/medication use and/or colonic irrigation, depending on the preferences of the patient. Use of PCT will be documented.