From the Guidelines
For diabetics, lactulose can be considered a viable laxative option, as it does not significantly increase blood sugar levels in mildly constipated, noninsulin-dependent patients with diabetes mellitus type 2 1. When managing constipation in diabetic patients, it is crucial to choose a laxative that does not adversely affect blood glucose levels.
- Osmotic laxatives like lactulose are a suitable choice, as they exert an osmotic effect in the colon to promote peristalsis without being digested in the small intestine.
- The recommended dose of lactulose is 10–20 g (15–30 mL or 1–2 packets) daily, which can be increased to 40 g (60 mL or 2–4 packets) daily if needed 1.
- However, it is essential to note that lactulose can cause dose-dependent side effects like bloating and flatulence, which may limit its use in some patients.
- Other options like polyethylene glycol (MiraLAX) and fiber supplements such as psyllium (Metamucil) or methylcellulose (Citrucel) can also be considered, as they have minimal impact on blood glucose levels.
- It is recommended to start with a daily dose of MiraLAX (17g powder dissolved in water) or 1 tablespoon of sugar-free Metamucil in water 1-3 times daily, and to drink plenty of water with any laxative.
- Stimulant laxatives like bisacodyl (Dulcolax) should be used only occasionally, as they can cause electrolyte imbalances.
- If constipation persists beyond a week despite laxative use, it is essential to consult a healthcare provider, as this could indicate a more serious condition.
From the Research
Laxative Options for Diabetics
- The aim of managing chronic constipation in patients with diabetes mellitus is to improve symptoms and restore bowel function by accelerating colonic transit and facilitating defecation 2.
- Treatment goals for diabetes-associated chronic constipation include improving symptoms and restoring bowel function, and should begin with food and dietary changes, exercise, and lifestyle changes 2.
- If these changes are not effective, laxatives should be the next step in treatment, starting with bulking agents such as psyllium, bran, or methylcellulose, followed by osmotic laxatives if response is poor 2.
Psyllium as a Laxative Option
- Psyllium is a soluble, gel-forming, non-fermented fiber supplement that has been shown to improve glycemic control in patients with type 2 diabetes mellitus (T2DM) 3.
- Psyllium supplementation has been found to improve glucose levels and insulin response, blood pressure, and lipid profile in both animals and humans, reducing metabolic risk factors 4, 5.
- The US Food and Drug Administration has authorized a health claim that psyllium husk can reduce the risk of heart disease, and has also considered a qualified health claim for the relationship between psyllium husk and a reduced risk of type 2 diabetes 5, 6.
Other Laxative Options
- Osmotic laxatives such as lactulose, polyethylene glycol, and lactitol are commonly prescribed for patients with diabetes-associated chronic constipation 2.
- Stimulants such as bisacodyl, sodium picosulphate, and senna are indicated if osmotic laxatives are not effective 2.
- Newer agents such as chloride-channel activators and 5-HT4 agonists can be considered for severe or resistant cases of constipation in patients with diabetes 2.