Table 6: Demonstrates the choices of mechanical bowel preparation that has been employed in those studies where the oral antibiotic bowel preparation has been demonstrated to be effective. There are many variations on these protocols.

Washington et al., 1974 [69] Nichols et al., 1973 [67]One day preparation

(i) Residue-free diet for 48 hours before operation.
(ii) Sodium phosphate and biphosphate 16 mL twice daily for 48 hours before operation.
(iii) Two tap water enemas two days before operation.
(iv) Two tap water enemas each on the morning and afternoon of the day before operation.
(v) 500 mg neomycin and 250 mg tetracycline taken four times daily for 48 hours before operation.
(i) Day 1: low residue diet; Bisacodyl, 1 capsule orally at 6 p.m.
(ii) Day 2: continue low residue diet; Magnesium sulfate, 30 mL. 50% solution (15 Gm.) orally at 10:00 a.m., 2:00 p.m., and 6:00 p.m; Saline enemas in evening until return clear
(iii) Day 3: clear liquid diet; supplemental IV fluids as needed. Magnesium sulfate, in dose above, at 10:00 a.m. and 2:00 p.m.No enemas. Neomycin (1 gm) and erythromycin base (1 gm) at 1300 hrs, 1400 hrs, and 2300 hrs.
(iv) Day 4: operation scheduled at 8:00 a.m.
Zhu et al., 2010 [87]
Day before procedure: 48 gms of sodium phosphate with 2 liters or more of water given the day before the procedure; if not clear, then saline enemas until clear with all completed by 1800 hrs. Then 2 g of neomycin and 2 g of metronidazole at 1900 and 2300 hrs.
Condon and Ludwig, 1995 [86]
Day before procedure: 4 liters of polyethylene glycol (60 gms) and salts (Colyte, Golytely) to be completed by 1200 hrs; then neomycin 1 g and erythromycin 1 g at 1300 hrs, 1400 hrs, and 2200 hrs.