SAGES Magazine

THE SOUTH AFRICAN GASTROENTEROLOGY REVIEW 2022 | VOLUME 20 | ISSUE 1 | 25 RESEARCH Table 4: Summary of risk of bias assessment using the Cochrane tool Study ID Risk of bias 1 Risk of bias 2 Risk of bias 3 Risk of bias 4 Risk of bias 5 Risk of bias 6 Risk of bias 7 Risk of bias Davis et al., 2006 [15] + + + ? - ? ? High risk of bias Hutchings 2011 [16] ? ? ? ? - ? ? High risk of bias Jia et al., 2010 [17] + + + ? + ? ? Moderate risk of bias Odes & Madar 1991 [18] ? ? ? ? + + ? Moderate risk of bias Sallon et al., 2002 [19] ? + + + + + ? Moderate risk of bias Størsrud et al., 2015 [14] ? + ? + + + ? Moderate risk of bias Bias 1: Random sequence generation (selection bias) Bias 2: Allocation concealment (selection bias) Bias 3: Blinding of participants and personnel (performance bias) Bias 4: Blinding of outcome assessment (detection bias) Bias 5: Incomplete outcome data (attrition bias) Bias 6: Selective reporting (reporting bias) Bias 7: Other bias 3.5. Adverse events Cases of adverse events were reported by three trials. 12,15,37 Given that these were few in number, the data were not pooled. One was the three-arm study 15 and the only adverse events were reported in Group A, which was not considered for the meta-analysis. This was the case of one patient developing diarrhoea, accompanied by abdominal pain after which the patient was advised to reduce dosage and the symptoms receded. Another study that dealt specifically with IBS-C patients 37 , reported that 10 out of the 34 patients in the experimental group had complained of mild side effects. These included 1 patient with nausea, 1 with a slight headache and 1 with hoarseness. In addition, 7 patients developed loose stools or diarrhoea, including 1 patient who also complained of a mild episode of shortness of breath, dizziness and chest pain, which was resolved within 24 hours. According to the protocol, patients who developed diarrhoea were to lower their dose by half. In the placebo group, 5 out of 27 patients reported side effects including 2 with abdominal pain, 1 with nausea and 2 with heartburn. In the third study that reported cases of adverse events, only 1 out of the 33 patients in the experimental group reported minor haemorrhoidal rectal bleeding, after which he withdrew from the study. After the study, this patient reported that he had occasional rectal bleeding five years before the study and that the current bleeding had stopped three days after he had stopped taking the Aloe and was not different from previous bleeding episodes. No adverse events were reported in the placebo group. All in all, when taking into consideration those studies included in the meta- analysis, 11 out of 168 (6%) in the experimental groups, and 5 out of 157 patients (3%) were reported to have developed mild side effects. 4. DISCUSSION 4.1. Principal Findings This systematic review found statistically significant evidence for Aloe-containing preparations being more effective than placebo in improving IBS symptoms overall. This finding was especially pronounced amongst IBS-C patients, regardless of the nature of the Aloe preparation. Among patients with diarrhea- predominant IBS (IBS-D), however, there is no evidence of Aloe’s effectiveness in improving symptoms. This work provides the first attempt at a systematic approach to summarizing the evidence of the effectiveness of Aloe in alleviating IBS symptoms. Laxatives are considered a primary measure for the treatment of IBS-C and functional constipation. The finding of Aloe’s effectiveness in improving constipation symptoms may be explained by Aloe’s laxative properties, which in turn, supports the biological plausibility of this finding. However, although laxatives such as Aloe have been shown to improve stool frequency, they have no proven effect on other symptoms such as bloating and abdominal pain 15 . Thus, it is possible that the effect of Aloe in