An oral liquid pharmaceutical composition comprising a plurality of extended release aminosalicylate microparticles provided with an enteric delayed release coating ("delayed/extended release aminosalicylate microparticles"), suspended in an aqueous liquid carrier formulated for oral administration, wherein the extended release aminosalicylate microparticles comprise an aminosalicylate formulated in an extended release matrix comprising an extended release polymer comprising one or more selected from cellulose acetate polymers and cellulose acetate butyrate polymers, wherein the enteric delayed release coating comprises one or more delayed release polymers selected from copolymers of methacrylic acid and methyl methacrylate, wherein the aqueous liquid carrier comprises a thixotropic agent selected from microcrystalline cellulose and a thickening agent selected from xanthan gum, wherein the oral liquid composition exhibits an in vitro dissolution profile such that, when subject to in vitro dissolution testing according to USP II Paddle at 37 °C and 100 rpm in 750 mL dissolution medium of pH 1.2 buffer for 2 hours, followed by pH 7 buffer for 12 hours, the oral liquid pharmaceutical composition exhibits substantially no release of aminosalicylate at pH 1.2, and release substantially all aminosalicylate within 3 to 8 hours ±10% at pH 7; and wherein the oral liquid composition is selected from an oral liquid pharmaceutical composition that comprises: (a) 4-8% w/w ± 10% aminosalicylate, 4-8% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:2, 5-12% w/w ±10% cellulose acetate, 0.8-1.2% w/w ±10% microcrystalline cellulose, 0.05-0.1% w/w ±10% xanthan gum, and water; (b) 2-6% w/w ± 10% aminosalicylate, 6-10% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:2, 5-12% w/w ±10% cellulose acetate butyrate, 0.8-1.2% w/w ±10% microcrystalline cellulose, 0.05-0.1% w/w ±10% xanthan gum, and water; (c) 4-5% w/w ±10% aminosalicylate, 3-8% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:1, 3-8% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:2, 3-8% w/w ±10% cellulose acetate butyrate, 0.5-1.5% w/w ± 10% microcrystalline cellulose, 0.05-0.1% w/w ±10% xanthan gum, and water; or (d) 4-5% w/w ± 10% aminosalicylate, 4-15% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:1, 1-5% w/w ± 10% poly(methacrylic acid-co-methyl methacrylate) 1:2, 3-9% w/w ±10% cellulose acetate butyrate, 0.5-1.5% w/w ±10% microcrystalline cellulose, 0.05-0.1% w/w ±10% xanthan gum, and water. wherein the enteric delayed release coating comprises one or more delayed release polymers selected from copolymers of methacrylic acid and methyl methacrylate, wherein the aqueous liquid carrier comprises a thixotropic agent selected from microcrystalline cellulose and a thickening agent selected from xanthan gum, wherein the oral liquid composition exhibits an in vitro dissolution profile such that, when subject to in vitro dissolution testing according to USP II Paddle at 37 °C and 100 rpm in 750 mL dissolution medium of pH 1.2 buffer for 2 hours, followed by pH 7 buffer for 12 hours, the oral liquid pharmaceutical composition exhibits substantially no release of aminosalicylate at pH 1.2, and release substantially all aminosalicylate within 3 to 8 hours ±10% at pH 7; and wherein the oral liquid composition is selected from an oral liquid pharmaceutical composition that comprises: (a) 4-8% w/w ± 10% aminosalicylate, 4-8% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:2, 5-12% w/w ±10% cellulose acetate, 0.8-1.2% w/w ±10% microcrystalline cellulose, 0.05-0.1% w/w ±10% xanthan gum, and water; (b) 2-6% w/w ± 10% aminosalicylate, 6-10% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:2, 5-12% w/w ±10% cellulose acetate butyrate, 0.8-1.2% w/w ±10% microcrystalline cellulose, 0.05-0.1% w/w ±10% xanthan gum, and water; (c) 4-5% w/w ±10% aminosalicylate, 3-8% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:1, 3-8% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:2, 3-8% w/w ±10% cellulose acetate butyrate, 0.5-1.5% w/w ± 10% microcrystalline cellulose, 0.05-0.1% w/w ±10% xanthan gum, and water; or (d) 4-5% w/w ± 10% aminosalicylate, 4-15% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:1, 1-5% w/w ± 10% poly(methacrylic acid-co-methyl methacrylate) 1:2, 3-9% w/w ±10% cellulose acetate butyrate, 0.5-1.5% w/w ±10% microcrystalline cellulose, 0.05-0.1% w/w ±10% xanthan gum, and water. (a) 4-8% w/w ± 10% aminosalicylate, 4-8% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:2, 5-12% w/w ±10% cellulose acetate, 0.8-1.2% w/w ±10% microcrystalline cellulose, 0.05-0.1% w/w ±10% xanthan gum, and water; (b) 2-6% w/w ± 10% aminosalicylate, 6-10% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:2, 5-12% w/w ±10% cellulose acetate butyrate, 0.8-1.2% w/w ±10% microcrystalline cellulose, 0.05-0.1% w/w ±10% xanthan gum, and water; (c) 4-5% w/w ±10% aminosalicylate, 3-8% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:1, 3-8% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:2, 3-8% w/w ±10% cellulose acetate butyrate, 0.5-1.5% w/w ± 10% microcrystalline cellulose, 0.05-0.1% w/w ±10% xanthan gum, and water; or (d) 4-5% w/w ± 10% aminosalicylate, 4-15% w/w ±10% poly(methacrylic acid-co-methyl methacrylate) 1:1, 1-5% w/w ± 10% poly(methacrylic acid-co-methyl methacrylate) 1:2, 3-9% w/w ±10% cellulose acetate butyrate, 0.5-1.5% w/w ±10% microcrystalline cellulose, 0.05-0.1% w/w ±10% xanthan gum, and water.