Of 514 patients hospitalized for miscellaneous hematologic diseases, 31 had severe anal lesions (5 per cent); these complications were most commonly observed in agranulocytosis, acute myeloid leukemia, and medullar aplasia. They included infiltration of the perianal area, ulceration, and abscesses. In 20 per cent of the 31 patients, the anal lesion was the first manifestation of the hematologic disease. In all instances, the prognosis of the condition was closely related to the type and severity of the underlying hematologic disease. Surgical therapy, which was applied to the majority of the abscesses, was followed in all instances by rapid symptomatic improvement and was never associated with local or general complications.

The study compared symptoms and manometric results in 76 patients (42 men and 34 women; median age: 45 years) before and at long-term follow-up (median time: 54 months) after fissurectomy with posterior midline sphincterotomy for anal fissure. The fissure healed in all cases. Sporadic loss of continence for flatus or for liquid stool occurred in 21 patients (27.6%) and soiling was present in 7 other patients (9.2%). Preoperative maximum resting anal pressure was significantly greater in the study group compared with 40 control subjects (p less than 0.001). Postoperative resting anal pressure fell significantly (p less than 0.001) and remained low on long-term assessment. Postoperative maximal squeeze pressure remained unchanged. No correlation could be found between preoperative and postoperative clinical symptoms (including continence) and anorectal manometry.

Background: The inhibition of thiopurine methyltransferase activity, one of the enzymes responsible for azathioprine metabolism, by aminosalicylates has been described in an in vitro study. This could result in a higher risk of bone marrow depression when using the two drugs together. Aim: To investigate the in vivo interaction between azathioprine and aminosalicylates in quiescent Crohn’s disease by measuring 6‐thioguanine nucleotide levels, thiopurine methyltransferase activity and the plasma levels of the acetylated metabolite of 5‐aminosalicylic acid. Methods: Sixteen patients taking a stable dose of azathioprine, plus sulfasalazine or mesalazine, were enrolled and completed the study. They were not taking any drugs interfering with azathioprine metabolism. Four visits every 4 weeks were held over a 3‐month period. Aminosalicylate administration was withdrawn after the second visit. At each visit, the blood cell count, inflammatory parameters, levels of 6‐thioguanine nucleotide and the acetylated metabolite of 5‐aminosalicylic acid and thiopurine methyltransferase activity were determined. Results: After aminosalicylate withdrawal, mean 6‐thioguanine nucleotide levels decreased significantly from 148 pmol (57–357 pmol) to 132 pmol (56–247 pmol) per 8 × 108 red blood cells (P=0.027), without significant changes in thiopurine methyltransferase activity or biological parameters. Conclusions: This in vivo study favours the existence of an interaction between azathioprine and aminosalicylates through a mechanism which remains unclear. This drug–drug interaction should be taken into account when using azathioprine and aminosalicylates simultaneously.