In the title compound, C(17)H(15)N(3)O(6)S, which crystallized with highly disordered methanol and/or water solvent mol-ecules, the dihedral angle between the the indole and benzene ring systems is 5.3 (2)°, which allows for the formation of intra-molecular π-π stacking inter-actions [centroid-centroid separations = 3.641 (3) and 3.694 (3) Å] and an approximate overall U-shape for the mol-ecule. In the crystal, dimers linked by pairs of N(s)-H⋯O(c) (s = sulfonamide and c = carboxyl-ate) hydrogen bonds generate R(2) (2)(10) loops, whereas N(i)-H⋯π (i = indole) inter-actions lead to chains propagating in [100] or [010]. Together, these lead to a three-dimensional network in which the solvent voids are present as inter-secting (two-dimensional) systems of [100] and [010] channels. The title compound was found to contain a heavily disordered solvent mol-ecule, which could be methanol or water or a mixture of the two. Due to its uncertain nature and the unresolvable disorder, the data were processed with the SQUEEZE option in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148-155], which revealed 877.8 Å(3) of solvent-accessible volume per unit cell and 126 electron-units of scattering density or 109.7 Å(3) (16 electron units) per organic mol-ecule.. This was not included in the calculations of overall formula weight, density and absorption coefficient.