Table 1.
Physiologic Differences Between Constipation-Predominant IBS and Functional Constipation
| Study | Population Studied | Measures | Results |
|---|---|---|---|
| Suttor et al17 | 25 FC patients vs 25 non-diarrhea-predominant IBS patients | DYS, BET | DYS was more prevalent in FC patients than IBS patients. Abnormal BET was more prevalent in IBS patients than FC patients. |
| Ansari et al18 | 50 FC patients vs 50 IBS-C patients | CTT (Sitzmark technique), segmental transit time | CTT was 52.2 hours in FC patients vs 41.2 hours in IBS-C patients (P=.10). Rectosigmoid transit was 19.9 hours in FC patients vs 11.9 hours in IBS-C patients (P=.003). |
| Shekhar et al4 | 11 FC patients vs 23 IBS-C patients; 23 HVs | 5-HT levels in serum, SBTT, CTT, PainTh | 5-HT levels were similar in FC patients and HVs, with both having higher levels than IBS-C patients. SBTT was similar in all groups. CTT was similar in FC patients and IBS-C patients, with both having longer CTT than HVs. PainTh was similar in FC patients and HVs, with lower thresholds in IBS-C patients. |
| Manabe et al19 | 287 IBS patients, including 118 IBS-C patients | CTT (scintigraphic technique). Abnormal is <10th percentile for HVs. | 22.9% of IBS-C patients had delayed transit at 48 hours vs 10.0% of HVs. |
| Tornblom et al20 | 359 IBS patients, including 100 IBS-C patients | CTT (Sitzmark technique) | CTT was delayed in 12% of IBS-C patients. |
| Mertz et al21 | 131 FC patients (82% also met the criteria for IBS-C) | CTT, DYS, PainTh | CTT was delayed in 47%. DYS was present in 59%. PainTh was abnormal in 58% and was uncorrelated with CTT or DYS. |
5-HT, 5-hydroxytryptamine; BET, balloon evacuation test; CTT, colonic transit time; DYS, dyssynergic defecation; FC, functional constipation; IBS, irritable bowel syndrome; IBS-C, constipation-predominant irritable bowel syndrome; HVs, healthy volunteers; PainTh, rectal threshold pressure or volume for pain or discomfort; SBTT, small bowel transit time.