This manuscript focuses on the numerical study of peristaltic flow of generalized Burgers' fluid through the gap between concentric uniform tubes (inner tube is rigid and outer tube is flexible) with an endoscope. The analysis has been carried out under the long wavelength and low Reynolds number approximations. The expressions of axial velocity, volume flow rate, pressure gradient and stream function are obtained by two different methods, namely; the homotopy perturbation method and the variational iteration method. The details of implementation of two methods are provided. Parametric study is performed at the end of the paper for analyzing the effects of emerging parameters on pressure‐rise per wavelength friction forces at the walls and trapping. It is found that pressure‐rise diminishes with increase in the magnitude of the first fractional parameter, second material constant and the ratio of radii of tubes, whereas the effect of second fractional parameter and other three material constants (first, third and fourth) on pressure‐rise is found to be the opposite. The influences of all these parameters on friction force (on the inner and outer tubes) are opposite to that of pressure‐rise. Copyright © 2011 John Wiley & Sons, Ltd.