Seventy nine mice and 18 gerbils were used in this experiment. The Chlorpromazine Group consisted of 39 mice and 12 gerbils. Each animal was injected with Chlorpromazine HQ 50 mg per kilogram body weight. Injections were administered twice a week for a period of 10 weeks. Clinical signs were only found in mice. Abdominal distention was transient in few animals and persisted in few others until the experiment was terminated. Few animals, without signs of meteorismus, developed priapismus and semenal discharge. The gut weight expressed in percentage of the total body weight of the enteromegalic mice was above 13 %, whereas that of the control animals varied between 6.3 % and 12.4 %. One gerbil developed segmental hydrosalpinx.Forty mice and 6 gerbils in the Sulfas Atropin Group were treated similarly as those of the Chlorpromazine Group, but injected with Atropini Sulfas daily at the rate of 0.330 mg to 0.660 mgper kilogram body weight for 14 or 20 days. Abdominal distention and/or enteromegaly did not occur at the termination of the experiment.