To provide a method for treating gastrointestinal disorders using a modified WNT
agonist and a modulator of the
WNT signaling pathway. [Solution] In one embodiment, the present disclosure includes an engineered WNT
agonist comprising (a) one or more binding domains that bind to one or more FZDs; and (b) one or more binding domains that bind to LRP5, LRP6, or both LRP5 and LRP6, wherein the polypeptide sequence has at least 90%, at least 95%, at least 98%, or at least 99%
sequence identity to any of SEQ ID NOs: 1 to 18, or a polypeptide sequence disclosed in any one of SEQ ID NOs: 1 to 25, Figure 2, Figure 6, Table 1, or Table 3, or a functional fragment or variant thereof, for example, its binding fragment, for example, a VHH domain, a
heavy chain variable domain, or a light chain
variable domain.