Figure 2  .

Decrease in maximum anal resting pressure (MARP) by isosorbide dinitrate (ID) and botulinum toxin (BT) in refractory anal fissure patients. Baseline shows mean internal anal sphincter (IAS) pressure in all fissure patients in the study before treatment. ID1, ID2, and ID3 indicate decreases in IAS pressures after 1.25, 2.50 and 3.75 mg of ID before any treatment. BT indicates mean IAS pressure in all study patients two weeks after BT injection. ID+BT indicates decrease in pressure with increasing dose of ID two weeks after BT injection.