Agent	Typical dosage*	Time of onset	Adverse effects
Bulking agents
Methylcellulose powder	19 g per day	12 to 72 hours	None compared with placebo¹⁷
Polycarbophil (Fibercon) tablets	1,250 mg, one to four times per day	12 to 72 hours	None recorded¹⁸
Psyllium (Metamucil) powder	1 tsp or 1 packet one to three times per day	12 to 24 hours	Bloating, abdominal distension in 4% to 18%^16,17
Osmotic laxatives
Lactulose solution	15 to 30 mL per day	24 to 48 hours	Bloating and cramping; nausea in up to 20%¹⁹
Magnesium citrate solution	150 to 300 mL, single dose or short-term daily dose	30 minutes to 6 hours	Increase in magnesium, causing lethargy, hypotension, respiratory depression²⁰
Magnesium hydroxide suspension	30 to 60 mL per day	30 minutes to 6 hours	Increase in magnesium, causing lethargy, hypotension, respiratory depression²⁰
Polyethylene glycol (Miralax) powder	17 g per day	24 to 48 hours	Minimal adverse effects of cramping and gas¹⁸
Sorbitol solution	2 to 3 tbsp, single dose or short-term daily dose	24 to 48 hours	Bloating, cramping, and nausea¹⁹
Stool softeners
Docusate sodium (Colace) capsules	100 mg twice per day	24 to 48 hours	None reported¹⁶
Stimulant laxatives
Bisacodyl (Dulcolax) tablets	5 to 15 mg per day	6 to 10 hours	Diarrhea and abdominal pain in 56% in week 1 and 5% in week 4²¹
Senna tablets	15 mg per day	6 to 12 hours	Abdominal pain in up to 12%¹⁶
Chloride channel activators
Lubiprostone (Amitiza)† capsules	24 mcg twice per day	Within 24 hours	Nausea in 18%²²
Peripherally acting mu-opioid antagonists
Methylnaltrexone (Relistor)‡ solution	Weight-based subcutaneous injection, once or twice per day	30 to 60 minutes	Diarrhea in 8% Abdominal pain in 13%²³
Other
Linaclotide (Linzess)† capsules	145 mcg per day	—	Diarrhea in 16%, which led to treatment cessation in 4%²⁴