| Bulk-forming |
| Methylcellulose (Citrucel) | Oral (powder or caplets): one to three times per day | 12 to 48 hours | $0.38 to $0.51 per day | Source of fiber; less gas formation compared with psyllium |
| Polycarbophil (Fibercon) | Oral (caplets): one to four times per day | 12 to 48 hours | $0.12 to $0.48 (generic) or $0.14 to $0.56 (brand) per day | May be ineffective if patient has pre-existing constipation or if patient is nonambulatory |
| Psyllium (Metamucil) | Oral (powder, wafer, or capsule): one to three times per day | 12 to 48 hours | Powder: $4.25 (generic) for 371 g or $8.17 (brand) for 390 g | Source of fiber; adequate water ingestion required (1,000 to 1,500 mL per day) |
| Capsule: $0.09 to $0.27 per day |
| Wafer: $0.18 to $0.55 per day |
| Osmotic |
| Lactulose | Oral (liquid): 15 to 60 mL per day | 24 to 48 hours | $10.51 to $32.40 per 480-mL bottle | More expensive than sorbitol |
| Polyethylene glycol (Miralax) | Oral (powder): 17 g (i.e., one capful) in 8 oz water daily | 24 to 48 hours | $2.11 per day | Lacks salty taste, making it a good option; more expensive than sorbitol |
| Sorbitol | Oral (liquid): 15 to 60 mL per day | 24 to 48 hours | $7.23 to $7.57 per 480-mL bottle | 70% solution; sweet taste |
| Saline |
| Magnesium citrate (Citroma) | Oral (liquid): 8 oz orally once; may repeat as needed | 0.5 to 3 hours | $1.49 per 300-mL bottle | Saline laxatives more useful on an as-needed basis; electrolyte imbalances are possible with all of the saline laxatives; use caution when prescribing to patients with declining renal function |
| Magnesium hydroxide (Milk of Magnesia) | Oral (liquid): 15 to 60 mL once; may repeat as needed | 0.5 to 3 hours | $3.05 (generic) or $3.53 (brand) per 360-mL bottle | |
| Sodium phosphate (Phospho-Soda) | Rectal: one adult enema | Within 30 minutes | $0.80 per bottle | |
| Stimulant |
| Bisacodyl (Dulcolax) | Oral: 10 to 15 mg one to three times per day | Oral: 6 to 12 hours | Oral: $0.13 to $0.49 (generic) or $0.40 to $1.20 (brand) per day | Not often used for opioid-induced constipation |
| Rectal: one suppository (10 mg) per day | Rectal: 15 to 60 minutes | Rectal: $0.24 (generic) or $0.86 (brand) per suppository |
| Senna | Oral (liquid or tablet): two tablets once per day to four tablets twice per day | 6 to 12 hours | $0.20 to $3.50 per day | Good first-line choice in those receiving chronic opioids |
| Stool softener |
| Docusate sodium (Colace) | Oral (capsule or liquid): 100 to 400 mg once or twice per day | 24 to 72 hours | $0.03 to $0.28 (generic) or $0.26 to $0.52 (brand) per day | Not effective as monotherapy for opioid-induced constipation; often used in combination with other laxatives |