This thesis evaluated chronic idiopathic constipation and the treatments used commonly in current clinical practice. Treatments evaluated included, biofeedback; delivered as nurse-led habit training (NBT), biofeedback; delivered as psycho-dynamic interpersonal therapy (PIT) and surgical outcome was explored in those who underwent stoma surgery. After performing a systematic review of the literature on non-invasive neuromodulation-based therapies, the most promising modalities identified were selected to examine further. Pilot studies on transcutaneous sacral nerve stimulation, bilateral transcutaneous tibial nerve stimulation and transabdominal interferential stimulation were performed.
At the end of NBT, 62.5% of the patients (217/347) reported reduced symptoms and 40.2% of the patients (n=41/102) reported a reduction of at least 1 point on the PAC-QOL score. The mean PAC-QOL scores before and after NBT were 2.42 and 1.41, respectively (P=.001). Multivariate analysis demonstrated that increasing age (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.02–2.87; P=.042), greater number of sessions (OR, 4.14; 95% CI, 2.09–8.20; P<.001), and non-irrigation (OR, 4.39; 95% CI, 1.89–10.19; P=.001) were independent predictors of patient satisfaction. Conversely, thirty-five patients (25 Female) commenced PIT treatment and 29/35 (82.9%) were followed up. The GAD-7 score improved significantly with treatment (median 17 pre-treatment, interquartile range (IQR) 4, to median 11 (6) post-treatment; p = <0.010). The HAD score improved (median 28 (7), to median 24 (11); p = 0.05) but this was influenced largely by improvement in anxiety sub-domains (median 17 pre-treatment, interquartile range (4), to median 13 (5) post-treatment; p = 0.007) and not in depression (median score 13 (5), to median 8 (6); p=0.011).
Overall, constipation symptoms improved in 37.9% of patients and this was more frequent in those with severe anxiety at baseline (p=0.003) and if anti-depressant medication was not taken (p=0.033). An analysis of patients undergoing surgery for constipation was performed. Short-term outcome of patients undergoing ostomy surgery was positive in 80% (16/24) of patients analysed. Fourteen patients (thirteen females, median age 47.5 years IQR 23-70) responded to the postal questionnaires (58.3%). Adverse effects on quality of life in the physical and social well-being domains was reported and a further 86% of respondents reporting psychological morbidity because of their stoma. However, more than 70% were satisfied (median follow-up 17 months IQR 0.16-8 years) with their quality of life despite a 20% re-operation rate. Of the 20 patients recruited to undergo transcutaneous sacral nerve stimulation, (16 female, median age 38.5 years) 80% (16/20) completed the trial. Five (31%) reported at least a point reduction in the Patient-Assessment of Constipation Symptoms score, 4 (25%) deteriorated and seven (44%) improved by less than one point. Median (inter quartile range) patient-Assessment of Constipation Symptoms scores were 2.33 (2.34) at baseline and 2.08 (2.58) at follow-up, p=0.074. Median scores for the Patient Assessment of Constipation Quality of Life and Cleveland systems were 3.00 (1.64) and 17.15 (18) at baseline and 2.22 (3.04) and 15.31 (12) at follow-up (p=0.096 and 0.111).
Patients underwent 6 weeks of daily bilateral transcutaneous tibial nerve stimulation (n=18) PAC-QOL score improved significantly with treatment (median 2.95 pre-treatment, interquartile range (IQR) 1.18, to median 2.50 post-treatment, IQR 0.70; P = 0.047). There was no change in PAC-SYM score (median 2.36, IQR 1.59, to median 2.08, IQR 0.92; P = 0.53). Weekly stool frequency improved as did VAS score but these did not reach significance (P= 0.229 and 0.161). Four patients (26%) improved both on PACQOL and PACSYM score. Two reported complete cure. Fourteen patients (12 female) completed four weeks of transabdominal interferential stimulation. There was no change in the PAC-QOL score (pre-treatment mean 2.80, interquartile range (IQR) 0.7; posttreatment, mean 2.70, IQR 0.50; p = 0.33]. There was no change in the PAC-SYM score (pre-treatment, mean 2.30, IQR 0.9; post-treatment, mean 2.10, IQR 0.8; P = 0.08). Weekly stool frequency did not improve (pre-treatment, mean 4.8, IQR 2.8; post-treatment mean 2.5, IQR 0.9; p= 0.07) but VAS score improved (pre-treatment, mean 4.3, IQR 7.6; post-treatment mean 22.9, IQR 26.7; p=0.02). No difference in efficacy was observed between IFC and TENS.
The off-label effect of Orlistat, on constipation symptoms, in patients awaiting surgery for constipation (n=7) demonstrated a PAC-QOL score improvement from 3.5 (interquartile range (IQR) 3.66-3.12) to 0.81 (IQR 2.37-0.09). Two reported cure of constipation symptoms and five deferred surgery owing to symptom improvement. Side effects of faecal incontinence was reported by four of the five responders. A median weight loss was 1.2kg at a median follow-up of ten weeks was observed.
Constipation is challenging to manage in patients with chronic symptoms. Of the current treatments available and investigated in this thesis, surgical stoma demonstrated the best outcome by improving symptoms in 67% of patients. Neuromodulation using non-invasive techniques did not improve symptoms of constipation for the majority.