Introduction One of psychiatric disorders associated with more physical symptoms is Obsessive compulsive disorder (OCD). Rectal prolapse is a rare entity but severe possible complication of OCD Case report A case of obsessive compulsive disorder with giant reducible rectal prolapse is reported. The patient experienced contamination obsessions, over washing, constipation and tenesmus, vigorous manual evacuation of bowel by fingers with feeling of incomplete and difficult to empty the bowel at defecation, even if the bowel contents have already been excreted. Her obsessions got better on Respridone and Clomipramine. Plan for surgery was put. Conclusion Giant rectal prolapse is a rare severe complication of OCD.
