A small randomized trial of lactulose vs dietary fiber showed both treatments to be effective in alleviating symptoms of diverticular disease.7 Two small case series of adults treated with dietary fiber found that fiber alleviated symptoms of diverticular disease,8,9 and possibly reduced complications of diverticulosis.9
We found no studies that investigated the common medical advice to avoid small nuts and seeds, which are thought to cause obstruction of the diverticuli and lead to diverticulitis.
TABLE
Studies on dietary fiber for diverticulosis
| TRIAL DESCRIPTION | INTERVENTION/COMPARISON | RESULTS |
|---|---|---|
| 20 adults with symptomatic diverticular disease diagnosed by barium enema. Randomized crossover trial5 | Bran tablets (18 g of fiber total) vs high roughage diet (HRD, amount of fiber unspecified) vs sterculia gum and antispasmodic | 20% were symptom free with a HRD, 40% with sterculia gum and antispasmodic, and 60% with bran tablets |
| 58 adults with uncomplicated symptomatic diverticular disease double-blind, crossover RCT, treated for 16 weeks with each intervention6 | Bran crispbread (6.99 g/d fiber), ispaghula (psyllium) husk drink (9.04 g/d fiber), and placebo (2.34 g/d fiber) | No significant difference among treatments for composite symptom scores. Stools were softer, more frequent, and straining with bowel movements was less with fiber supplements (P<.001) |
| 43 adults with symptomatic diverticular disease. Randomized trial7 | Lactulose 15 mL bid vs high-fiber diet (30–40 g/d) for 12 weeks | Pain frequency with a bowel movement was reduced with lactulose (P=.017). Pain severity was reduced with lactulose (P=.028) and high fiber diet (P=.043). Abdominal pain frequency was decreased with lactulose (P=.0015) and with a high fiber diet (P=.022). Abdominal pain severity was decreased with lactulose (P=.009) and with a high fiber diet (P=.028) |
| 40 adults with symptomatic diverticular disease diagnosed by barium enema. Case series8 | Wheat bran 24 g/d for at least 6 months | The 40 patients had 391 total symptoms, and 60% were abolished, 28% relieved |
| 100 adults with a history of symptomatic diverticular disease. Case series9 | High-fiber diet (40 g/d) | 91% of patients remained asymptomatic over 5 to 7 years, although only 75% adhered to their high-fiber diet |
Recommendations by others
The American College of Gastroenterology states that it is reasonable to recommend a diet high in fruit and vegetable fiber to patients with uncomplicated diverticulosis.10