Scotty, the Tyrranosaurus Rex from Eastend, Saskatchewan left evidence of his passing besides his huge skeleton. One drawing produced by the Eastend community Tourism Authority shows him sauntering out of an outhouse, looking greatly relieved!

Fossil feces have been studied as early as 1829 by Rev. William Buckland, Professor of Geology at Oxford University, who coined an appropriate name for these fossil objects -- coprolite, Greek for "dung rock". Coprolites are fairly common fossil objects, but dinosaur coprolites are rare and those that can be attributed to carnivorous dinosaurs are virtually unknown.
The pride of Saskatchewan, Scotty the Tyrannosaur, has recently been excavated outside the small town of Eastend where the Eastend Fossil Research Station has been established to prepare the dinosaur skeleton and, in general, to promote paleontology in the southwest corner of the province. In 1995 a large, whitish-grey lump, half a metre long and weighing over 7 kg, was discovered a few kilometres away from Scotty's bones. Although fossil crocodiles and small theropods are known from Upper Cretaceous rocks in this area, only a tyrannosaur could have produced something of that volume. In fact, this was the largest single feces ever recorded from any carnivore, fossil or living.
The coprolite was packed with bone fragments up to 3 cm long set in a fine grained phosphatic groundmass. Even though the bone fragments were rounded and corroded by enzymes and stomach acids, they were obviously pieces of shattered bone originally. This observation calls into question the view of some dinosaur paleontologists that Tyrannosaurus, like living carnivorous reptiles, swallowed its prey whole (remember the celebrated lawyer scene in Jurassic Park). The shattered bone packed in the coprolite suggests that the tyrannosaur pulverized, consumed and digested large quantities of bone along with flesh, skin and organs. These are feeding characteristics of an efficient predator -- one that wasted little and extracted food value from every bit of the carcass. Tim Tokaryk, the paleontologist studying the large head of Scotty, commented, "We figured from studying the front end that they could crush bones. Now that we're looking at the other end, we've confirmed that".

Further reading:
Chin, K., Tokaryk, T.T., Erickson, G.M. and Calk, L.C.
1998: A king-sized theropod coprolite. Nature, vol. 393, p. 680-682.
Horner, J.R. and Lessem, D.
1993: The Complete T. rex. Simon & Schuster, 238 p.