Intestinal motility was examined in an animal model of intestinal anaphylaxis. Hooded-Lister rats were sensitized (S) by intraperitoneal injection of 10 micrograms egg albumin (Ag) and compared with sham-sensitized controls (C). Seven days later three bipolar jejunal electrodes and a jejunostomy tube for motility recording and Ag administration were implanted. On day 14 intestinal myoelectric and motor activity were measured in fasted animals before and after intraluminal administration of either 10 mg egg albumin in 0.5 ml saline, 10 mg bovine serum albumin (BSA) in 0.5 ml saline, or placebo (P) challenge with 0.5 ml saline. Specific immunoglobulin E serum titers were greater than or equal to 1:64 in S animals, whereas C animals showed no response. None of the C animals challenged with P or Ag and none of the S animals challenged with P or BSA defecated after challenge, but all the S animals challenged with Ag developed diarrhea (P less than 0.001). In S animals challenged with Ag, the fasting motility pattern was disrupted, the migrating motor complex was abolished (P = 0.002), and the frequency of aborally propagating clustered contractions was increased (P less than 0.01). In this animal model an immune-mediated reaction to food protein was associated with diarrhea and altered intestinal myoelectric and motor activity.