EVALUATION OF ANORECTAL PHYSIOLOGY IN PATIENTS WITH INCREASED MAST-CELLS

Diarrhea, urgency, and fecal incontinence are common complaints in sys temic mastocytosis and in patients with increased gastrointestinal muc osal mast cells. We performed anorectal manometry on six patients with clinical symptoms of mastocytosis and histologic evidence of increase d mast cells and compared the results to anorectal manometry of six ag e- and sex-matched controls, with no bowel symptoms. Standard techniqu es with balloon volumes were used to measure maximal basal pressure, m aximal squeeze pressure, smallest volume sensed, degree of relaxation of the internal sphincter, and the volume causing: (1) a strong urge t o defecate and (2) pain. Patients with mastocytosis, compared with con trols, had smaller balloon volumes induce rectal urgency (97 vs 164 ml ) and pain (117 vs 278 ml). A trend was present for lower maximal basa l pressure in mastocytosis, but was not statistically significant. Sen sitivity to balloon inflation suggests decreased rectal compliance or overreactive rectal contractility. These findings provide an explanati on for the anorectal symptoms in patients with increased mast cells.