A further area where evidence for policy is lacking is the use of metronidazole in severely malnourished children. The WHO guidelines recommend "Metronidazole 7.5 mg/kg every 8 h for 7 days may be given in addition to broad-spectrum antibiotics; however, the efficacy of this treatment has not been established in clinical trials." Metronidazole is effective against anaerobic bacteria, small bowel bacterial overgrowth, Clostridium difficile colitis and also Giardia, which is common amongst children with SAM. Small cohort studies of metronidazole usage suggest there may be benefits for nutritional recovery in malnourished children. However, metronidazole can cause nausea and anorexia, potentially impairing recovery from malnutrition and may also rarely cause liver and neurological toxicity.