The invention relates to a device for collecting stool samples, comprising: a disposable laminar body (1) having a shape suitable for being positioned on the rear part of the hole in the seat of a toilet, such that the front part of the hole remains unobstructed, ensuring that urine is not mixed with faeces. The device is characterised in that the laminar body (1) comprises a central opening (2) with securing means (3) provided around same, for removably securing a water-soluble stool collection bag (4), such that, once the stool sample has been collected, only the water-soluble bag (4), together with any remaining faeces, is disposed of down the toilet, while the laminar body (1) can be disposed of elsewhere. Upon coming into contact with the water, the bag degrades quickly, facilitating the collection of samples and the disposal of the bag.
