Colonic and small intestinal response to intravenous prostaglandin F2 alpha and E2 in man

The effects of intravenous infusions of prostaglandins (PGs) F2 alpha(0-4 or 0-8 mug kg-1 min-1) or E2 (0-08 or 0-1 mug kg-1 min equals1) on net colonic movement of water and electrolytes and on ileal flow were measured in eight healthy males by simultaneous ileal and colonic perfusion. Ileal flow was increased by PGF2 alpha (six subjects) from a mean of 1-69 ml min-1 to 4-63 ml min-1 (P smaller than 0-01); it also increased in the two subjects given PGE2. Colonic absorptive function was not significantly diminished by either prostaglandin. These results suggest that diarrhoea due to prostaglandins originates in the small intestine.