How to manage constipation in patients with diverticulitis?

Managing Constipation in Diverticulitis

For patients with a history of diverticulitis experiencing constipation, prioritize a high-fiber diet from whole foods (targeting >22 g/day) supplemented with osmotic laxatives like polyethylene glycol when needed, while strictly avoiding NSAIDs and opiates that worsen both constipation and diverticulitis risk. 1

Dietary Management as First-Line Therapy

A fiber-rich diet is the cornerstone of constipation management in diverticulitis patients. The American Gastroenterological Association recommends high fiber intake from fruits, vegetables, whole grains, and legumes for patients with a history of diverticulitis 2, 1. This recommendation carries conditional strength with very low-quality evidence, but the intervention poses minimal risk and aligns with broader health benefits 2.

Specific Fiber Targets and Sources

• Target fiber intake should exceed 22.1 g/day for protective effects against diverticular disease complications 1.
• Fiber from fruits appears to have stronger protective associations compared to other fiber sources 1.
• Fiber supplementation (such as psyllium) can be beneficial but should complement, not replace, a high-quality whole food diet 2, 1.
• When starting fiber supplementation, begin with one dose per day and gradually increase to three doses daily as the body adjusts to prevent bloating 3.

Critical Foods NOT to Avoid

Patients should NOT avoid nuts, seeds, popcorn, or corn – these foods are not associated with increased diverticulitis risk and may actually be protective 2, 1, 4. This outdated restriction unnecessarily reduces overall fiber intake and should be abandoned 1.

Laxative Management When Fiber Alone Is Insufficient

When dietary fiber alone does not adequately manage constipation, osmotic laxatives like polyethylene glycol (MiraLAX) are recommended 1. These agents work synergistically with fiber and do not carry the risks associated with stimulant laxatives.

• Ensure adequate hydration (at least 8 ounces of water with each fiber dose) to support fiber effectiveness and prevent constipation 1, 3.
• If using psyllium, mix with a full glass of water and drink promptly; if mixture thickens, add more liquid 3.

Critical Medications to AVOID

NSAIDs - Major Risk Factor

Avoid non-aspirin NSAIDs whenever possible – they increase the risk of recurrent diverticulitis and can worsen constipation 2, 1, 4. The AGA suggests against routine use of nonaspirin NSAIDs in patients with a history of diverticulitis 2.

• Aspirin prescribed for cardiovascular disease secondary prevention can be continued, as it carries lower risk than other NSAIDs 2, 4.

Opiates - Dual Threat

Avoid opiate analgesics – they are associated with both constipation and increased risk of diverticulitis and perforation 1, 4. This creates a dangerous cycle where treating pain worsens the underlying condition.

Lifestyle Modifications

• Encourage vigorous physical activity – this decreases diverticulitis risk and promotes regular bowel function 2, 1, 4.
• Maintain normal body mass index – obesity is an established risk factor for diverticulitis 1, 4.
• Smoking cessation is essential – smoking increases diverticulitis risk 4.

When Chronic Symptoms Persist Despite Conservative Management

If constipation and abdominal symptoms persist after an episode of diverticulitis:

• Exclude ongoing inflammation with both CT imaging and lower endoscopy before attributing symptoms to functional causes 2.
• Alternative diagnoses to consider include ischemic colitis, inflammatory bowel disease, diverticular stricture, or fistula 2.
• If no inflammation is found, visceral hypersensitivity is the likely cause – this affects approximately 45% of patients at 1-year follow-up 2.
• For visceral hypersensitivity, low to modest doses of tricyclic antidepressants may be considered for their neuromodulatory effects on bowel function 2, 1.

Special Considerations for Post-Surgical Patients

For patients with prior bowel resection for diverticulitis:

• Be aware that 25% experience long-term complications including abdominal distention, cramping, altered defecation, and fecal incontinence 2, 1.
• If constipation is refractory to conservative management, consider evaluation for anastomotic stricture with imaging and endoscopy 1.
• Gastroenterology referral is appropriate for refractory symptoms or concerns about surgical complications 1.

Medications NOT Recommended

Do not prescribe mesalamine, rifaximin, or probiotics for prevention of recurrent diverticulitis or constipation management – the AGA recommends against these interventions as they have no proven benefit 2, 1, 4.

Red Flags Requiring Urgent Evaluation

Seek immediate medical attention if the patient develops:

• Fever, severe uncontrolled pain, or persistent nausea/vomiting 1
• Inability to tolerate oral intake or signs of bowel obstruction 1
• Rectal bleeding or failure to have a bowel movement after 7 days of constipation 3
• These may indicate recurrent diverticulitis, perforation, or surgical complications 1

Common Pitfalls to Avoid

• Do not recommend unnecessarily restrictive diets that eliminate nuts, seeds, or high-fiber foods – this reduces overall fiber intake and is not evidence-based 1, 4.
• Do not rely solely on fiber supplements without improving overall diet quality – supplements should complement whole foods, not replace them 1, 4.
• Warn patients about potential temporary bloating when starting high-fiber regimens to improve adherence 2, 1.
• Do not assume lifestyle modifications alone will prevent all recurrences – approximately 40-50% of diverticulitis risk is attributable to genetic factors 4.