Marc Kaneshiro

Long-term Risk of Acute Diverticulitis Among Patients With Incidental Diverticulosis Found During Colonoscopy

BACKGROUND & AIMS Colonic diverticulosis is the most common finding during routine colonoscopy, and patients often question the significance of these lesions. Guidelines state that these patients have a 10% to 25% lifetime risk of developing acute diverticulitis. However, this value was determined based on limited data, collected before population-based colonoscopy, so the true number of cases of diverticulosis was not known. We measured the long-term risk of acute diverticulitis among patients with confirmed diverticulosis discovered incidentally on colonoscopy. METHODS We performed a retrospective study using administrative and clinical data from the Veterans Affairs Greater Los Angeles Healthcare System, collecting data on patients who underwent colonoscopies from January 1996 through January 2011. We identified patients diagnosed with diverticulosis, determined incidence rates per 1000 patient-years, and analyzed a subgroup of patients with rigorously defined events confirmed by imaging or surgery. We used a Cox proportional hazards model to identify factors associated with the development of diverticulitis. RESULTS We identified 2222 patients with baseline diverticulosis. Over an 11-year follow-up period, 95 patients developed diverticulitis (4.3%; 6 per 1000 patient-years); of these, 23 met the rigorous definition of diverticulitis (1%; 1.5 per 1000 patient-years). The median time-to-event was 7.1 years. Each additional decade of age at time of diagnosis reduced the risk for diverticulitis by 24% (hazard ratio, 0.76; 95% confidence interval, 0.6-0.9). CONCLUSIONS Based on a study of the Veterans Affairs Greater Los Angeles Healthcare System, only about 4% of patients with diverticulosis develop acute diverticulitis, contradicting the common belief that diverticulosis has a high rate of progression. We also found that younger patients have a higher risk of diverticulitis, with risk increasing per year of life. These results can help inform patients with diverticulosis about their risk of developing acute diverticulitis.

Development and validation of a novel patient educational booklet to enhance colonoscopy preparation.

OBJECTIVES:The success of colonoscopy depends on high-quality bowel preparation by patients; yet inadequate preparation is common. We developed and tested an educational booklet to improve bowel preparation quality.METHODS:We conducted patient cognitive interviews to identify knowledge and belief barriers to colonoscopy preparation. We used these interviews to create an educational booklet to enhance preparatory behaviors. We then prospectively randomized patients scheduled for outpatient colonoscopy at a VA Medical Center to receive usual instructions vs. the booklet before colonoscopy. Patients in both groups received standard pharmacy instructions for single-dose bowel preparation; the protocol did not specify which purgatives to prescribe. The primary outcome was preparation quality based on blinded ratings using the validated Ottawa score. We performed bivariate analyses to compare mean scores between groups using a t-test, and logistic regression to measure the booklet effect on preparation quality, adjusting for potential confounders.RESULTS:A total of 436 patients were randomized between arms. In an intention-to-treat analysis of the primary outcome, mean Ottawa scores were superior in patients allocated to booklet vs. controls (P=0.03). An intention-to-treat analysis of the secondary outcome revealed a “good” preparation in 68 vs. 46% of booklet and control patients, respectively (P=0.054). In a per-protocol analysis limited to patients who actually received the booklet, preparation was good in 76 vs. 46% patients, respectively (P<0.00001). Regression analysis revealed that booklet receipt increased the odds of good preparation by 3.7 times (95% confidence interval=2.3–5.8).CONCLUSIONS:Provision of a novel educational booklet considerably improves preparation quality in patients receiving single-dose purgatives. The effect of the booklet on split-dose purgatives remains untested and will be evaluated in future research.

Increased Risk for Irritable Bowel Syndrome After Acute Diverticulitis

BACKGROUND & AIMS Individuals with diverticulosis frequently also have irritable bowel syndrome (IBS), but there are no longitudinal data to associate acute diverticulitis with subsequent IBS, functional bowel disorders, or related emotional distress. In patients with postinfectious IBS, gastrointestinal disorders cause long-term symptoms, so we investigated whether diverticulitis might lead to IBS. We compared the incidence of IBS and functional bowel and related affective disorders among patients with diverticulitis. METHODS We performed a retrospective study of patients followed up for an average of 6.3 years at a Veterans Administration medical center. Patients with diverticulitis were identified based on International Classification of Diseases, 9th revision codes, selected for the analysis based on chart review (cases, n = 1102), and matched with patients without diverticulosis (controls, n = 1102). We excluded patients with prior IBS, functional bowel, or mood disorders. We then identified patients who were diagnosed with IBS or functional bowel disorders after the diverticulitis attack, and controls who developed these disorders during the study period. We also collected information on mood disorders, analyzed survival times, and calculated adjusted hazard ratios. RESULTS Cases were 4.7-fold more likely to be diagnosed later with IBS (95% confidence interval [CI], 1.6-14.0; P = .006), 2.4-fold more likely to be diagnosed later with a functional bowel disorder (95% CI, 1.6-3.6; P < .001), and 2.2-fold more likely to develop a mood disorder (CI, 1.4-3.5; P < .001) than controls. CONCLUSIONS Patients with diverticulitis could be at risk for later development of IBS and functional bowel disorders. We propose calling this disorder postdiverticulitis IBS. Diverticulitis appears to predispose patients to long-term gastrointestinal and emotional symptoms after resolution of inflammation; in this way, postdiverticulitis IBS is similar to postinfectious IBS.