Enteritis cystica profunda and diffuse colitis cystica profunda are exceedingly rare conditions. We report here the first case in which these two entities are associated in one patient. This 48-year-old woman presented initially with a solitary ulcer of the rectum and developed later deep ileal and colonic ulcerations with intervening normal mucosa, polypoid masses, and a dense fibrosis of the bowel wall. Colon and ileum specimens demonstrated submucosal mucous cysts and occasionally herniation of mucosal epithelium into the submucosa, which led to the diagnosis of enteritis and colitis cystica profunda. The exact nature of the underlying ileocolonic disease, which necessitated colectomy and extensive ileal resection, remained undetermined although an aggravating role of iterative surgical procedures is possible. Enteritis cystica profunda and diffuse colitis cystica profunda therefore seem to share a common pathogeny and have to be considered as lesions complicating an underlying disease rather than specific and autonomic diseases.